1. The study examined the effect of occupation on hearing loss using data from 49,948 participants in Norway.
2. Occupation explained an additional 2-3% of the variance in hearing loss for men ages 45 and older, beyond what was explained by age alone.
3. Controlling for reported noise exposure reduced the occupational effect by 20-40% for men ages 45 and older, but occupation effects were small for women and younger men.
Voice Assessments for Detecting Patients with Parkinson’s Diseases in Differe...IJECEIAES
This document summarizes a study that aimed to classify 375 voice samples into 4 groups (healthy, early PD, intermediate PD, advanced PD) based on 19 extracted voice features. The most relevant features were selected using PCA. Classification was performed using k-fold cross-validation and SVM with linear, quadratic, and cubic kernels. The best result was 92.5% accuracy using PCA and linear SVM. Quadratic SVM achieved 87.5% accuracy and cubic SVM 85.1% accuracy. The study demonstrates that voice assessments can effectively detect Parkinson's disease and distinguish its different stages.
Predicted impairment and handicap from exposure to steady state broad-band in...Alexander Decker
This academic article summarizes research on predicting impairment and handicap from exposure to steady-state broad-band industrial noise. The researchers used empirical formulas to predict monaural impairment and hearing handicap values for different exposure levels. They found that both impairment and handicap increase with exposure level, supporting the equal energy hypothesis. The values of hearing handicap were always higher than impairment values.
Retention Through Recognition: Keeping Your High Performers USMotivation
The document discusses the benefits of exercise for mental health. Regular physical activity can help reduce anxiety and depression and improve mood and cognitive functioning. Exercise causes chemical changes in the brain that may help boost feelings of calmness, happiness and focus.
This document provides a strategic analysis of Daurala Sugar Works, a unit of DCM Shriram Group located in Daurala, Uttar Pradesh. It begins with an executive summary describing the company and Indian sugar industry. It then analyzes the industry, introducing the company and outlining its operations. The document discusses government regulations, the company's financial performance, human resources, social commitments and future prospects. It concludes with recommendations to help guide the company's future strategic direction.
This document defines and explains the key elements of a negotiable instrument under Indian law. It begins by defining a negotiable instrument as a written document that creates a right to a certain sum of money and can be freely transferred through delivery or endorsement. It then discusses some key characteristics of negotiable instruments, including their free transferability without formalities, the holder in due course taking the instrument free from defects in title, and the transferee's ability to sue in their own name. The document also covers types of negotiable instruments recognized by law and by custom, presumptions that apply, and definitions and elements of specific instruments like promissory notes and bills of exchange.
Voice Assessments for Detecting Patients with Parkinson’s Diseases in Differe...IJECEIAES
This document summarizes a study that aimed to classify 375 voice samples into 4 groups (healthy, early PD, intermediate PD, advanced PD) based on 19 extracted voice features. The most relevant features were selected using PCA. Classification was performed using k-fold cross-validation and SVM with linear, quadratic, and cubic kernels. The best result was 92.5% accuracy using PCA and linear SVM. Quadratic SVM achieved 87.5% accuracy and cubic SVM 85.1% accuracy. The study demonstrates that voice assessments can effectively detect Parkinson's disease and distinguish its different stages.
Predicted impairment and handicap from exposure to steady state broad-band in...Alexander Decker
This academic article summarizes research on predicting impairment and handicap from exposure to steady-state broad-band industrial noise. The researchers used empirical formulas to predict monaural impairment and hearing handicap values for different exposure levels. They found that both impairment and handicap increase with exposure level, supporting the equal energy hypothesis. The values of hearing handicap were always higher than impairment values.
Retention Through Recognition: Keeping Your High Performers USMotivation
The document discusses the benefits of exercise for mental health. Regular physical activity can help reduce anxiety and depression and improve mood and cognitive functioning. Exercise causes chemical changes in the brain that may help boost feelings of calmness, happiness and focus.
This document provides a strategic analysis of Daurala Sugar Works, a unit of DCM Shriram Group located in Daurala, Uttar Pradesh. It begins with an executive summary describing the company and Indian sugar industry. It then analyzes the industry, introducing the company and outlining its operations. The document discusses government regulations, the company's financial performance, human resources, social commitments and future prospects. It concludes with recommendations to help guide the company's future strategic direction.
This document defines and explains the key elements of a negotiable instrument under Indian law. It begins by defining a negotiable instrument as a written document that creates a right to a certain sum of money and can be freely transferred through delivery or endorsement. It then discusses some key characteristics of negotiable instruments, including their free transferability without formalities, the holder in due course taking the instrument free from defects in title, and the transferee's ability to sue in their own name. The document also covers types of negotiable instruments recognized by law and by custom, presumptions that apply, and definitions and elements of specific instruments like promissory notes and bills of exchange.
The Impact of Information and Communications Technologies on the Teaching of...Hicham El Moueden
This document provides an overview and analysis of the use of information and communications technologies (ICT) in foreign language teaching and learning in Europe. It begins with an executive summary that outlines key findings. The document then discusses its methodology, objectives, and structure. It provides an overview of current ICT uses, presents case studies of best practices, and examines future prospects. It concludes with recommendations, including the need for ongoing teacher training to fully realize the benefits of ICT for improving foreign language education. Experts believe ICT will play an increasingly important role, enabling more collaboration and independent learning. However, more work is still needed to understand how ICT can systematically support language acquisition.
Statistics Case Study - Stepwise Multiple RegressionSharad Srivastava
The document describes using stepwise multiple regression to develop a model for forecasting fish landings. It discusses selecting independent variables like fishermen, fishing boats, and fishing gears. Two models are built and compared. Model 2, with fishermen and fishing gears as independent variables, best fits the data with 47.9% of variation explained. The model will help forecast fish landings using these key factors.
PI n PSI India Pvt. Ltd. has proposed developing a new variable interest management system for YourMoney. The system will use a web-based front end and back end processes to automatically calculate fluctuating interest rates. A team of 7 specialists in areas like project management, financial markets, mainframes, and web technologies will complete the 9 month project for approximately Rs. 20.23 lakh. Successful implementation would provide YourMoney with automated interest calculations, improved risk management, and regulatory reporting capabilities.
This document provides an overview of South Africa in 12 sections. It begins with an introduction to South Africa's location, population, government, and economy. Next, it discusses South Africa's history from Dutch colonization to the end of apartheid. The document then analyzes South Africa's political, economic, socio-cultural, technological, legal, and environmental landscape. It concludes by examining future challenges and recommendations for South Africa. The report aims to comprehensively analyze South Africa's current situation and future prospects.
Term Paper - Quality Assurance in Software DevelopmentSharad Srivastava
This document provides an overview of software quality assurance. It discusses the evolution of SQA from an initial focus on "code and ship" in the 1960s-1980s to today's emphasis on SQA processes. Key concepts covered include quality, quality control, quality assurance, and the cost of quality. Elements of SQA like activities and models are described. Leading organizations' SQA practices are examined through case studies. The document aims to explain the importance of SQA for software development organizations.
This document provides an analysis of the sugar industry and marketing strategies of Daurala Sugar Works, a unit of DCM Shriram Group located in Daurala, Uttar Pradesh, India. It begins with an executive summary that outlines the purpose and scope of the study. It then discusses the sugar industry in India, providing statistics on production levels and the key role of the industry. An introduction to Daurala Sugar Works is given. The document analyzes the competitive landscape of the sugar industry using Porter's Five Forces model. It also discusses the cyclical nature of the sugar industry and Daurala Sugar Works' marketing strategies. The conclusion provides a future outlook and recommendations.
The document proposes establishing i'Live, a combination multiplex and food court, in Roorkee, India. It notes Roorkee's population supports such a business but currently lacks quality entertainment and dining options together. The proposal recommends constructing a 3-screen multiplex operated by a major brand and a food court with global fast food chains. Financial projections estimate i'Live will reach break-even within 5 years of opening. The marketing strategy focuses on creating awareness and establishing i'Live as a one-stop destination through superior service quality and ambience.
This document presents a business case for implementing a supply chain management (SCM) package at Sobeys Inc., the second largest food retailer in Canada. Sobeys has over 1,500 stores across 10 provinces and 25 distribution centers, but currently uses different applications for different functions. This causes issues like poor inventory management and lack of communication across the supply chain. The business case evaluates measurable organizational values, total costs and benefits, financial analysis, alternatives, and risks of implementing an integrated SCM system. It recommends SCM to drive visibility, optimize planning and execution, improve inventory management and cash flow, and strategically manage transportation and logistics across Sobeys' large network.
This document provides an overview of microfinance in India. It defines microfinance and its key features. It discusses the evolution of microfinance in India since the 1970s. It describes the different models of microfinance delivery including self-help groups (SHGs), joint liability groups (JLGs), microfinance institutions (MFIs), and the priority sector lending framework. It summarizes the recommendations of the Malegam Committee on regulating the microfinance sector in India. Finally, it provides some statistics on the growth and current status of microfinance in India.
This document discusses risk management in banks. It outlines the major types of risks banks face: credit risk, market risk, and operational risk. Credit risk is the potential that a bank borrower fails to meet obligations and can take the form of outright default or deterioration in credit quality. Market risk includes liquidity risk, interest rate risk, foreign exchange risk, and country risk due to fluctuations in market values. Operational risk is the risk of loss from inadequate internal processes or systems. The Basel Accords provide capital adequacy guidelines for banks to manage unexpected losses from risks based on their risk profiles. Risk management in banks involves identifying, measuring, monitoring, and controlling various risks to ensure sufficient capital levels are maintained.
Electronic mail, more commonly known as email, allows digital messages to be exchanged between an author and one or more recipients. Email systems operate over computer networks like the Internet using a store-and-forward model where email servers accept, forward, deliver, and store messages. An email consists of a message envelope, header, and body. Originally text-only, email was later extended to support multimedia attachments. While early versions required both parties to be online simultaneously, modern email systems allow users to connect briefly to send or receive messages without needing to be online at the same time.
The document discusses Porter's five forces model as it applies to the apparel industry. It analyzes the competitive intensity and profitability of the industry by looking at the barriers to entry, power of suppliers and buyers, threat of substitutes, and rivalry among existing competitors. The summary is:
[1] The apparel industry has high barriers to entry due to economies of scale, significant capital requirements, and intense competition from established brands.
[2] Suppliers have bargaining power when materials are unique or undifferentiated, while buyers wield power in bulk purchases or when many supplier options exist.
[3] Substitute brands pose a threat if switching costs are low based on quality or status.
Current trends in audiological practices and implications for developing coun...Alexander Decker
- Current audiological practices in developing countries still rely heavily on behavioral audiometric testing which requires active patient participation, while developed countries now emphasize electrophysiological testing that does not require active participation.
- Electrophysiological tests like auditory brainstem response testing and otoacoustic emission testing provide objective measures of hearing. Developed countries also use advanced techniques like cochlear implants.
- To better diagnose and treat hearing loss early, some developed countries implement universal newborn hearing screening before 1 month of age to identify problems, with evaluation by 3 months and early intervention starting by 6 months if needed. Early diagnosis and treatment are important for language development.
This academic article discusses noise pollution in a steel fabrication industry and its impacts on worker health. It measures noise levels at different locations in the industry and examines how prolonged industrial noise exposure affects hearing capacity through worker interviews and clinical examinations. The article finds that most workers report issues like lack of concentration and headaches from noise. Clinical tests show some workers have permanent hearing threshold shifts or mild to moderate hearing loss due to long-term noise exposure.
Hearing loss among elderly patients in an ear clinic in nigeriaAlexander Decker
This study investigated hearing loss patterns among elderly patients seen at an ear clinic in Nigeria. Of the 586 patients who underwent audiometry over 3 years, 88 (15%) were elderly (age 65+). The mean age was 72.4 years and most were males. Over 80% had hearing loss, and 82% of those had disabling hearing loss. While sensorineural hearing loss was most common, mixed and conductive hearing losses were also present. Moderately severe hearing loss was the most prevalent. The majority had a sloping audiometric pattern typical of presbycusis, but other patterns occurred as well. Disabling hearing loss is very common in the elderly and often goes unaddressed, risking social
Noise can negatively impact human health in several ways. Prolonged exposure to noise levels over 85 dB(A) is likely to cause hearing loss, while even lower levels can cause sleep disturbance, cardiovascular effects, and impaired cognitive performance in children. Noise is considered a psychosocial stressor that activates the body's stress response. Epidemiological studies have found associations between transportation noise over 65-70 dB(A) and increased risks of cardiovascular disease. Future research should further examine how different noise sources and levels impact health risks.
A cochlear implant consists of internal and external components that convert sound waves to electrical impulses and transmit them to the inner ear, allowing hearing without reading lips. Speech and language ability varies among individuals, with many developing age-appropriate skills. However, cochlear implants carry risks such as facial paralysis or meningitis from infection. Early identification and treatment of hearing loss benefits children's development, with studies showing better language scores for children who begin intervention before age 12 months.
Hearing health of live music sound engineers - HEARing CRC PhD presentationHEARnet _
When listened to for too loud, for too long, music can incur the same hearing damage as experienced by those exposed to occupational noise.1 Rock/pop musicians have been well documented as being ‘at risk’ of such damage,3 yet little has been done to investigate if Live Music Sound Engineers, at the core of the live-music experience, are also at risk.
This document summarizes a study on treating muscle tension dysphonia. The study examined 11 patients with muscle tension dysphonia over one year. Both primary and secondary muscle tension dysphonia cases were included. All patients received voice therapy. Outcomes were measured before and after therapy using auditory-perceptual ratings, quality of life measures, and visual-perceptual laryngeal evaluations. Results found voice therapy to be very effective for improving muscle tension dysphonia based on improved scores on all outcome measures after therapy. The document concludes voice therapy should be the primary treatment for both primary and secondary muscle tension dysphonia cases.
This study investigated the prevalence of four otologic (ear-related) complaints (otalgia, tinnitus, vertigo, hearing loss) in 200 patients with temporomandibular disorder (TMD) and compared it to a control group without TMD. The study found that TMD patients reported significantly higher rates of otologic complaints than the control group, with over three-quarters of TMD patients reporting at least one complaint. Otalgia was the most commonly reported complaint across the different TMD subgroups. However, there were only a small number of patients that had objective evidence of hearing loss related to their subjective complaints. The study suggests TMD may be associated with increased reports of otologic symptoms.
Effects of Mobile Phones on Auditory acuity. Dr. Balaji P.A, Dr. Kailash N.pdfDrBalaji8
This document summarizes a study that evaluated the effects of mobile phone use on auditory acuity. The study compared hearing thresholds between 300 mobile phone users and 100 non-users based on pure tone audiometry. Results found statistically significant increases in hearing thresholds among mobile users at certain frequencies. Specifically, thresholds were higher for mobile users at 1kHz, 4kHz, 6kHz and 8kHz frequencies compared to non-users. Dominant ears (those used for calls more often) also had higher thresholds than non-dominant ears at some frequencies among mobile users. However, the duration and amount of mobile use did not correlate with hearing thresholds. The study concludes mobile use may mildly impair hearing but further research is
Effects of Mobile Phones on Auditory acuity. Dr. Balaji P.A, Dr. Kailash N.pdfDrBalaji8
RJMS 2011;1(1):25-30.
Abstract
Background and Objectives: There is an exponential
increase in the usage of mobile phones throughout the
world. Mobile phone handsets are usually held near
the ear during conversations and these phones emit
radiations (electromagnetic fields). These radiations
have a propensity to cause biological health hazards.
This has raised the question of whether the usage of
mobile phones has any detrimental effects on the
hearing of the user. The aim of this study was to
evaluate the auditory acuity in normal subjects using
mobile phones and subjects not using.
Methods: A total 400 subjects were selected
considering inclusion and exclusion criteria. Among
these 300 were mobile users and 100 non-users. These
two groups were subjected to pure tone audiometric
assessment. The resulting data was statistically
analyzed.
Results: There was an increase in the hearing
thresholds with p-value <0.05 at frequencies of lkhz
(BC), 4khz (AC and BC), 6khz(AC) and 8khz(AC) in
the mobile phone users compared to that in non-users.
The thresholds in the dominant ear were increased
with p-value <0.05 at frequencies lkhz(AC and BC),
2khz(AC and BC), 4khz(AC and BC), 6khz(AC) that
compared in non-dominant ear. The different duration
of exposures (in months) and the average time
(min/day) exposures did not have any significant
effect on the hearing thresholds.
Conclusion: There is a mild increase in the hearing
thresholds in mobile users, but the probable cause of
hearing impairment cannot be proved by this study
and the possible pathophysiology is also not
understood and it needs to be investigated further...
Key words: Mobile phones, electromagnetic fields
(EMF), Pure tone audiometry, Air conduction (AC),
Bone conduction (BC).
The Impact of Information and Communications Technologies on the Teaching of...Hicham El Moueden
This document provides an overview and analysis of the use of information and communications technologies (ICT) in foreign language teaching and learning in Europe. It begins with an executive summary that outlines key findings. The document then discusses its methodology, objectives, and structure. It provides an overview of current ICT uses, presents case studies of best practices, and examines future prospects. It concludes with recommendations, including the need for ongoing teacher training to fully realize the benefits of ICT for improving foreign language education. Experts believe ICT will play an increasingly important role, enabling more collaboration and independent learning. However, more work is still needed to understand how ICT can systematically support language acquisition.
Statistics Case Study - Stepwise Multiple RegressionSharad Srivastava
The document describes using stepwise multiple regression to develop a model for forecasting fish landings. It discusses selecting independent variables like fishermen, fishing boats, and fishing gears. Two models are built and compared. Model 2, with fishermen and fishing gears as independent variables, best fits the data with 47.9% of variation explained. The model will help forecast fish landings using these key factors.
PI n PSI India Pvt. Ltd. has proposed developing a new variable interest management system for YourMoney. The system will use a web-based front end and back end processes to automatically calculate fluctuating interest rates. A team of 7 specialists in areas like project management, financial markets, mainframes, and web technologies will complete the 9 month project for approximately Rs. 20.23 lakh. Successful implementation would provide YourMoney with automated interest calculations, improved risk management, and regulatory reporting capabilities.
This document provides an overview of South Africa in 12 sections. It begins with an introduction to South Africa's location, population, government, and economy. Next, it discusses South Africa's history from Dutch colonization to the end of apartheid. The document then analyzes South Africa's political, economic, socio-cultural, technological, legal, and environmental landscape. It concludes by examining future challenges and recommendations for South Africa. The report aims to comprehensively analyze South Africa's current situation and future prospects.
Term Paper - Quality Assurance in Software DevelopmentSharad Srivastava
This document provides an overview of software quality assurance. It discusses the evolution of SQA from an initial focus on "code and ship" in the 1960s-1980s to today's emphasis on SQA processes. Key concepts covered include quality, quality control, quality assurance, and the cost of quality. Elements of SQA like activities and models are described. Leading organizations' SQA practices are examined through case studies. The document aims to explain the importance of SQA for software development organizations.
This document provides an analysis of the sugar industry and marketing strategies of Daurala Sugar Works, a unit of DCM Shriram Group located in Daurala, Uttar Pradesh, India. It begins with an executive summary that outlines the purpose and scope of the study. It then discusses the sugar industry in India, providing statistics on production levels and the key role of the industry. An introduction to Daurala Sugar Works is given. The document analyzes the competitive landscape of the sugar industry using Porter's Five Forces model. It also discusses the cyclical nature of the sugar industry and Daurala Sugar Works' marketing strategies. The conclusion provides a future outlook and recommendations.
The document proposes establishing i'Live, a combination multiplex and food court, in Roorkee, India. It notes Roorkee's population supports such a business but currently lacks quality entertainment and dining options together. The proposal recommends constructing a 3-screen multiplex operated by a major brand and a food court with global fast food chains. Financial projections estimate i'Live will reach break-even within 5 years of opening. The marketing strategy focuses on creating awareness and establishing i'Live as a one-stop destination through superior service quality and ambience.
This document presents a business case for implementing a supply chain management (SCM) package at Sobeys Inc., the second largest food retailer in Canada. Sobeys has over 1,500 stores across 10 provinces and 25 distribution centers, but currently uses different applications for different functions. This causes issues like poor inventory management and lack of communication across the supply chain. The business case evaluates measurable organizational values, total costs and benefits, financial analysis, alternatives, and risks of implementing an integrated SCM system. It recommends SCM to drive visibility, optimize planning and execution, improve inventory management and cash flow, and strategically manage transportation and logistics across Sobeys' large network.
This document provides an overview of microfinance in India. It defines microfinance and its key features. It discusses the evolution of microfinance in India since the 1970s. It describes the different models of microfinance delivery including self-help groups (SHGs), joint liability groups (JLGs), microfinance institutions (MFIs), and the priority sector lending framework. It summarizes the recommendations of the Malegam Committee on regulating the microfinance sector in India. Finally, it provides some statistics on the growth and current status of microfinance in India.
This document discusses risk management in banks. It outlines the major types of risks banks face: credit risk, market risk, and operational risk. Credit risk is the potential that a bank borrower fails to meet obligations and can take the form of outright default or deterioration in credit quality. Market risk includes liquidity risk, interest rate risk, foreign exchange risk, and country risk due to fluctuations in market values. Operational risk is the risk of loss from inadequate internal processes or systems. The Basel Accords provide capital adequacy guidelines for banks to manage unexpected losses from risks based on their risk profiles. Risk management in banks involves identifying, measuring, monitoring, and controlling various risks to ensure sufficient capital levels are maintained.
Electronic mail, more commonly known as email, allows digital messages to be exchanged between an author and one or more recipients. Email systems operate over computer networks like the Internet using a store-and-forward model where email servers accept, forward, deliver, and store messages. An email consists of a message envelope, header, and body. Originally text-only, email was later extended to support multimedia attachments. While early versions required both parties to be online simultaneously, modern email systems allow users to connect briefly to send or receive messages without needing to be online at the same time.
The document discusses Porter's five forces model as it applies to the apparel industry. It analyzes the competitive intensity and profitability of the industry by looking at the barriers to entry, power of suppliers and buyers, threat of substitutes, and rivalry among existing competitors. The summary is:
[1] The apparel industry has high barriers to entry due to economies of scale, significant capital requirements, and intense competition from established brands.
[2] Suppliers have bargaining power when materials are unique or undifferentiated, while buyers wield power in bulk purchases or when many supplier options exist.
[3] Substitute brands pose a threat if switching costs are low based on quality or status.
Current trends in audiological practices and implications for developing coun...Alexander Decker
- Current audiological practices in developing countries still rely heavily on behavioral audiometric testing which requires active patient participation, while developed countries now emphasize electrophysiological testing that does not require active participation.
- Electrophysiological tests like auditory brainstem response testing and otoacoustic emission testing provide objective measures of hearing. Developed countries also use advanced techniques like cochlear implants.
- To better diagnose and treat hearing loss early, some developed countries implement universal newborn hearing screening before 1 month of age to identify problems, with evaluation by 3 months and early intervention starting by 6 months if needed. Early diagnosis and treatment are important for language development.
This academic article discusses noise pollution in a steel fabrication industry and its impacts on worker health. It measures noise levels at different locations in the industry and examines how prolonged industrial noise exposure affects hearing capacity through worker interviews and clinical examinations. The article finds that most workers report issues like lack of concentration and headaches from noise. Clinical tests show some workers have permanent hearing threshold shifts or mild to moderate hearing loss due to long-term noise exposure.
Hearing loss among elderly patients in an ear clinic in nigeriaAlexander Decker
This study investigated hearing loss patterns among elderly patients seen at an ear clinic in Nigeria. Of the 586 patients who underwent audiometry over 3 years, 88 (15%) were elderly (age 65+). The mean age was 72.4 years and most were males. Over 80% had hearing loss, and 82% of those had disabling hearing loss. While sensorineural hearing loss was most common, mixed and conductive hearing losses were also present. Moderately severe hearing loss was the most prevalent. The majority had a sloping audiometric pattern typical of presbycusis, but other patterns occurred as well. Disabling hearing loss is very common in the elderly and often goes unaddressed, risking social
Noise can negatively impact human health in several ways. Prolonged exposure to noise levels over 85 dB(A) is likely to cause hearing loss, while even lower levels can cause sleep disturbance, cardiovascular effects, and impaired cognitive performance in children. Noise is considered a psychosocial stressor that activates the body's stress response. Epidemiological studies have found associations between transportation noise over 65-70 dB(A) and increased risks of cardiovascular disease. Future research should further examine how different noise sources and levels impact health risks.
A cochlear implant consists of internal and external components that convert sound waves to electrical impulses and transmit them to the inner ear, allowing hearing without reading lips. Speech and language ability varies among individuals, with many developing age-appropriate skills. However, cochlear implants carry risks such as facial paralysis or meningitis from infection. Early identification and treatment of hearing loss benefits children's development, with studies showing better language scores for children who begin intervention before age 12 months.
Hearing health of live music sound engineers - HEARing CRC PhD presentationHEARnet _
When listened to for too loud, for too long, music can incur the same hearing damage as experienced by those exposed to occupational noise.1 Rock/pop musicians have been well documented as being ‘at risk’ of such damage,3 yet little has been done to investigate if Live Music Sound Engineers, at the core of the live-music experience, are also at risk.
This document summarizes a study on treating muscle tension dysphonia. The study examined 11 patients with muscle tension dysphonia over one year. Both primary and secondary muscle tension dysphonia cases were included. All patients received voice therapy. Outcomes were measured before and after therapy using auditory-perceptual ratings, quality of life measures, and visual-perceptual laryngeal evaluations. Results found voice therapy to be very effective for improving muscle tension dysphonia based on improved scores on all outcome measures after therapy. The document concludes voice therapy should be the primary treatment for both primary and secondary muscle tension dysphonia cases.
This study investigated the prevalence of four otologic (ear-related) complaints (otalgia, tinnitus, vertigo, hearing loss) in 200 patients with temporomandibular disorder (TMD) and compared it to a control group without TMD. The study found that TMD patients reported significantly higher rates of otologic complaints than the control group, with over three-quarters of TMD patients reporting at least one complaint. Otalgia was the most commonly reported complaint across the different TMD subgroups. However, there were only a small number of patients that had objective evidence of hearing loss related to their subjective complaints. The study suggests TMD may be associated with increased reports of otologic symptoms.
Effects of Mobile Phones on Auditory acuity. Dr. Balaji P.A, Dr. Kailash N.pdfDrBalaji8
This document summarizes a study that evaluated the effects of mobile phone use on auditory acuity. The study compared hearing thresholds between 300 mobile phone users and 100 non-users based on pure tone audiometry. Results found statistically significant increases in hearing thresholds among mobile users at certain frequencies. Specifically, thresholds were higher for mobile users at 1kHz, 4kHz, 6kHz and 8kHz frequencies compared to non-users. Dominant ears (those used for calls more often) also had higher thresholds than non-dominant ears at some frequencies among mobile users. However, the duration and amount of mobile use did not correlate with hearing thresholds. The study concludes mobile use may mildly impair hearing but further research is
Effects of Mobile Phones on Auditory acuity. Dr. Balaji P.A, Dr. Kailash N.pdfDrBalaji8
RJMS 2011;1(1):25-30.
Abstract
Background and Objectives: There is an exponential
increase in the usage of mobile phones throughout the
world. Mobile phone handsets are usually held near
the ear during conversations and these phones emit
radiations (electromagnetic fields). These radiations
have a propensity to cause biological health hazards.
This has raised the question of whether the usage of
mobile phones has any detrimental effects on the
hearing of the user. The aim of this study was to
evaluate the auditory acuity in normal subjects using
mobile phones and subjects not using.
Methods: A total 400 subjects were selected
considering inclusion and exclusion criteria. Among
these 300 were mobile users and 100 non-users. These
two groups were subjected to pure tone audiometric
assessment. The resulting data was statistically
analyzed.
Results: There was an increase in the hearing
thresholds with p-value <0.05 at frequencies of lkhz
(BC), 4khz (AC and BC), 6khz(AC) and 8khz(AC) in
the mobile phone users compared to that in non-users.
The thresholds in the dominant ear were increased
with p-value <0.05 at frequencies lkhz(AC and BC),
2khz(AC and BC), 4khz(AC and BC), 6khz(AC) that
compared in non-dominant ear. The different duration
of exposures (in months) and the average time
(min/day) exposures did not have any significant
effect on the hearing thresholds.
Conclusion: There is a mild increase in the hearing
thresholds in mobile users, but the probable cause of
hearing impairment cannot be proved by this study
and the possible pathophysiology is also not
understood and it needs to be investigated further...
Key words: Mobile phones, electromagnetic fields
(EMF), Pure tone audiometry, Air conduction (AC),
Bone conduction (BC).
Effects of Mobile Phones on Auditory acuity. Dr. Balaji P.A, Dr. Kailash N.pdfDrBalaji8
Abstract
Background and Objectives: There is an exponential
increase in the usage of mobile phones throughout the
world. Mobile phone handsets are usually held near
the ear during conversations and these phones emit
radiations (electromagnetic fields). These radiations
have a propensity to cause biological health hazards.
This has raised the question of whether the usage of
mobile phones has any detrimental effects on the
hearing of the user. The aim of this study was to
evaluate the auditory acuity in normal subjects using
mobile phones and subjects not using.
Methods: A total 400 subjects were selected
considering inclusion and exclusion criteria. Among
these 300 were mobile users and 100 non-users. These
two groups were subjected to pure tone audiometric
assessment. The resulting data was statistically
analyzed.
Results: There was an increase in the hearing
thresholds with p-value <0.05 at frequencies of lkhz
(BC), 4khz (AC and BC), 6khz(AC) and 8khz(AC) in
the mobile phone users compared to that in non-users.
The thresholds in the dominant ear were increased
with p-value <0.05 at frequencies lkhz(AC and BC),
2khz(AC and BC), 4khz(AC and BC), 6khz(AC) that
compared in non-dominant ear. The different duration
of exposures (in months) and the average time
(min/day) exposures did not have any significant
effect on the hearing thresholds.
Conclusion: There is a mild increase in the hearing
thresholds in mobile users, but the probable cause of
hearing impairment cannot be proved by this study
and the possible pathophysiology is also not
understood and it needs to be investigated further...
Key words: Mobile phones, electromagnetic fields
(EMF), Pure tone audiometry, Air conduction (AC),
Bone conduction (BC).
I apologize, upon reviewing the document and video you provided, I do not see enough context to accurately summarize or analyze them. Could you please provide more details about what you would like me to focus on? Summarizing without full context runs the risk of missing important details or perspectives.
Introduction
Epidemiology
Pathophysiology
Sign and symptoms
Complication and investigations
Evaluation
Diagnosis
Prevention and management
Treatment
PrognosisSudden
sensorineural hearing loss
It is one of three type of hearing loss
Hearing loss due to defect in the sensory apparatus cochlea (sensory)
Or in the pathway of conduction of nerve impulses to the brain (neural)
Neural causes can be
peripheral:8 nerve
Central:auditory pathway or cortex
Hearing loss is very common among the elderly, affecting around 25-40% of those over 65 and up to 80% of those over 85. It is typically caused by presbycusis, or age-related hearing loss, which results in a gradual, progressive, bilateral sensorineural hearing loss most prominent in higher frequencies. While the hearing loss cannot be reversed, it can be well-managed through the use of hearing aids, auditory training, speech reading, and clear communication strategies to help the elderly maintain quality of life. Proper assessment of hearing loss involves audiometry to measure sensitivity across frequencies and classify the degree of loss.
Presbycusis and noise induced hearing lossUtpal Sarmah
This document discusses noise induced hearing loss (NIHL). It defines NIHL and notes it is usually sensorineural, bilateral, and symmetrical initially affecting higher frequencies. NIHL can be temporary (TTS) or permanent (PTS). It affects about 10% of the global workforce and is the second most common cause of hearing loss. The pathophysiology involves metabolic changes like oxidative stress and structural changes to hair cells and supporting structures. Diagnosis involves audiometry typically showing a notch at 4 kHz. Prevention focuses on hearing protection, noise control, and early treatment.
This document discusses instrumentation used to measure acoustic signals and auditory function. It describes otoacoustic emissions, which are sounds emitted from the inner ear that can be measured in the ear canal. There are two types of otoacoustic emissions: spontaneous and evoked. Transient evoked otoacoustic emissions and distortion product otoacoustic emissions are the most clinically applicable evoked emissions. These emissions are present in normal hearing but absent in hearing loss, making them useful for hearing screening and diagnosis. The document also discusses transient evoked otoacoustic emission testing specifically, noting it is a quick, sensitive test using a small probe to detect cochlear pathology for uses such as neonatal hearing screening, differential diagnosis
HOW TO BROACH A MUSCLE TENSION DYSPHONIA CASE
Sachender Pal Singh (PGT), Aakanksha Rathor (PGT), Smrity Rupa Borah Dutta
ABSTRACT
Muscle Tension Dysphonia (MTD) is a condition where excessive muscular tension or
muscle misuse is associated with phonation. It has multifactorial etiologies. It can be a
primary or secondary Muscle Tension Dysphonia. While it can affect anyone, sufferers
usually belong to a particular group. It has very serious impact on sufferer's personal, social
& professional life. We are presenting here, our 1 year prospective study done in the
department of Otorhinolaryngology, Silchar Medical College & Hospital from June 2012 to
July 2013. Voice therapy was given to every patient whether primary or secondary muscle
tension dysphonia & Pre therapy-versus-post therapy comparisons were made of selfratings
of Voice Handicap Index, Auditory-Perceptual Ratings, as well as, Visual -
Perceptual Evaluations of laryngeal images. Outcome of voice therapy results in such
patients were found to be very good. As the disease is multifactorial so treatment approach
should be broad based involving multidisciplinary team
Dtsch arztebl int- loss sensorineural hearingAdriana Galván
This document discusses sudden idiopathic sensorineural hearing loss, which refers to sudden, unilateral hearing loss of unknown cause originating from the inner ear. Epidemiological studies show it has an incidence of up to 300 cases per 100,000 people per year in Germany. The cause is unclear but may involve various pathophysiological mechanisms like hypoperfusion or infection that damage inner ear structures. Diagnostic tests aim to distinguish it from other causes of acute hearing loss and rule out conditions like middle ear effusion. While treatments like steroids and plasma expanders show some evidence of benefit, no high-quality clinical trials have validated any treatment. Further research is still needed.
Adhd Medication Shortage Uk - trinexpharmacy.comreignlana06
The UK is currently facing a Adhd Medication Shortage Uk, which has left many patients and their families grappling with uncertainty and frustration. ADHD, or Attention Deficit Hyperactivity Disorder, is a chronic condition that requires consistent medication to manage effectively. This shortage has highlighted the critical role these medications play in the daily lives of those affected by ADHD. Contact : +1 (747) 209 – 3649 E-mail : sales@trinexpharmacy.com
Muktapishti is a traditional Ayurvedic preparation made from Shoditha Mukta (Purified Pearl), is believed to help regulate thyroid function and reduce symptoms of hyperthyroidism due to its cooling and balancing properties. Clinical evidence on its efficacy remains limited, necessitating further research to validate its therapeutic benefits.
Integrating Ayurveda into Parkinson’s Management: A Holistic ApproachAyurveda ForAll
Explore the benefits of combining Ayurveda with conventional Parkinson's treatments. Learn how a holistic approach can manage symptoms, enhance well-being, and balance body energies. Discover the steps to safely integrate Ayurvedic practices into your Parkinson’s care plan, including expert guidance on diet, herbal remedies, and lifestyle modifications.
Hiranandani Hospital in Powai, Mumbai, is a premier healthcare institution that has been serving the community with exceptional medical care since its establishment. As a part of the renowned Hiranandani Group, the hospital is committed to delivering world-class healthcare services across a wide range of specialties, including kidney transplantation. With its state-of-the-art facilities, advanced medical technology, and a team of highly skilled healthcare professionals, Hiranandani Hospital has earned a reputation as a trusted name in the healthcare industry. The hospital's patient-centric approach, coupled with its focus on innovation and excellence, ensures that patients receive the highest standard of care in a compassionate and supportive environment.
8 Surprising Reasons To Meditate 40 Minutes A Day That Can Change Your Life.pptxHolistified Wellness
We’re talking about Vedic Meditation, a form of meditation that has been around for at least 5,000 years. Back then, the people who lived in the Indus Valley, now known as India and Pakistan, practised meditation as a fundamental part of daily life. This knowledge that has given us yoga and Ayurveda, was known as Veda, hence the name Vedic. And though there are some written records, the practice has been passed down verbally from generation to generation.
Promoting Wellbeing - Applied Social Psychology - Psychology SuperNotesPsychoTech Services
A proprietary approach developed by bringing together the best of learning theories from Psychology, design principles from the world of visualization, and pedagogical methods from over a decade of training experience, that enables you to: Learn better, faster!
Cell Therapy Expansion and Challenges in Autoimmune DiseaseHealth Advances
There is increasing confidence that cell therapies will soon play a role in the treatment of autoimmune disorders, but the extent of this impact remains to be seen. Early readouts on autologous CAR-Ts in lupus are encouraging, but manufacturing and cost limitations are likely to restrict access to highly refractory patients. Allogeneic CAR-Ts have the potential to broaden access to earlier lines of treatment due to their inherent cost benefits, however they will need to demonstrate comparable or improved efficacy to established modalities.
In addition to infrastructure and capacity constraints, CAR-Ts face a very different risk-benefit dynamic in autoimmune compared to oncology, highlighting the need for tolerable therapies with low adverse event risk. CAR-NK and Treg-based therapies are also being developed in certain autoimmune disorders and may demonstrate favorable safety profiles. Several novel non-cell therapies such as bispecific antibodies, nanobodies, and RNAi drugs, may also offer future alternative competitive solutions with variable value propositions.
Widespread adoption of cell therapies will not only require strong efficacy and safety data, but also adapted pricing and access strategies. At oncology-based price points, CAR-Ts are unlikely to achieve broad market access in autoimmune disorders, with eligible patient populations that are potentially orders of magnitude greater than the number of currently addressable cancer patients. Developers have made strides towards reducing cell therapy COGS while improving manufacturing efficiency, but payors will inevitably restrict access until more sustainable pricing is achieved.
Despite these headwinds, industry leaders and investors remain confident that cell therapies are poised to address significant unmet need in patients suffering from autoimmune disorders. However, the extent of this impact on the treatment landscape remains to be seen, as the industry rapidly approaches an inflection point.
REGULATION FOR COMBINATION PRODUCTS AND MEDICAL DEVICES.pptx
250 engdahl
1. Original article
Scand J Work Environ Health 2010;36(3):250–257
Occupation and the risk of hearing impairment – results from the Nord-
Trøndelag study on hearing loss
by Bo Engdahl, PhD,1 Kristian Tambs, PhD 1, 2
Engdahl B, Tambs K. Occupation and the risk of hearing impairment – results from the Nord-Trøndelag study on
hearing loss. Scand J Work Environ Health. 2010;36(3):250–257.
Objectives We studied the effect of occupation on hearing and if it remained after adjustment for noise
e
xposure, education, income, and other risk factors.
Methods Audiometry and a questionnaire concerning exposure was administered to a general adult population
sample in Norway (N=49 948). Information on occupation, education, and income was obtained from popula-
tion census registers.
Results Occupation had marked effects on hearing loss. Occupation explained 2–3% of the variance in hearing
loss among men ≥45 years in addition to the hearing loss due to age (10–19%). Occupation explained ≤1% of
hearing loss among women of all ages and young men. Controlling for self-reported occupational noise exposure
reduced the occupational effect by 20–40% in men ≥45 years. Controlling for leisure-time noise, ear infections,
and head injuries did not change the effect of occupation, which was slightly reduced after controlling for edu-
cation and income. The most elevated hearing thresholds in men were observed among: wood workers; miners;
linemen and cable jointers; construction carpenters and workers; seamen; and workshop mechanics.
Conclusions There was a moderate association between occupation and hearing loss. Unbiased estimates
of occupational hearing loss may help identify high-risk occupations, for which interventions are needed, and
identify individuals with hearing loss.
Key terms audiometry; epidemiology; noise exposure; Norway; occupational health; prevalence.
Hearing loss is one of the most common health problems prominent occupational diseases (3, 7). Sectors with a
in the industrialized world (1); the World Health Orga- high reported prevalence include agriculture, forestry,
nization (WHO) regards adult-onset hearing loss as the fishing, mining and quarrying, extraction, energy and
fifteenth most serious health problem. (2). According to water supply, manufacturing, and construction (3).
the European Survey on Working Conditions (3), about Established prevalence estimates by health authori-
7% of European workers consider that their work affects ties are based on the number of reported cases, which
their health in the form of hearing disorders. Occupa- may be biased. The threshold for reporting cases can
tional risk factors for hearing loss include occupational vary among sectors and countries. Specifically, the num-
noise, whole body vibration, work-related diseases, and ber of reported cases may be influenced by the level of
exposure to toxins. impairment required for financial compensation or pen-
According to the WHO, about 16% of disabling hear- sion eligibility; it may also be confounded by subjective
ing loss worldwide is attributable to occupational noise beliefs about noise exposure or other risk factors and
exposure (4, 5). This estimate was based on established whether normal hearing is vital for work performance.
risk estimates and noise exposure data from the US For example, the Swedish Work Environment Author-
National Institute for Occupational Safety and Health, ity reports that nursery schools are one of the noisiest
mainly from 1981–1983 (6). The European Union also work environments for women in Sweden, with a high
recognizes noise-induced hearing loss as one of the most rate of reported noise-related hearing losses (8). But
1 Norwegian Institute of Public Health, Division of Mental Health, Oslo, Norway.
2 Department of Psychiatry and Human Genetics, Virginia Commonwealth University, Richmond, VA, USA.
Correspondence to: Dr B Engdahl, Norwegian Institute of Public Health, Division of Mental Health, Box 4404 Nydalen, N-0403 Oslo,
Norway. [E-mail: bo.engdahl@fhi.no]
250 Scand J Work Environ Health 2010, vol 36, no 3
2. Engdahl & Tambs
such reporting may result from an elevated awareness years to 82% for subjects from 60–69 years. The low
of hearing problems in teachers or a work environment participation rate among young people was partly caused
that demands good hearing; these factors may result in by the non-appearance of students and young persons
over-reporting of hearing loss. The actual hearing of doing their (compulsory) military service who, while
nursery school teachers has not yet been studied in a formally keeping their childhood home address, had
systematic way. moved to other parts of the country.
There is thus a need for unbiased estimates of occu- A total of 51 574 persons arrived for their hearing
pational hearing loss in the population. Epidemiologic examination and provided written informed consent.
studies of occupation-specific, work-related hearing loss Audiometric data were missing for 774 persons (1.5%).
are needed in order to identify high-risk occupations, in Questionnaire data were missing or incomplete for
which specific types of harmful exposure are identified 815 persons (1.6%). The sample is described in greater
and protection is provided. detail elsewhere (9). Information on occupation and
Previous analyses of data from the Nord-Trøndelag education was obtained for all but 37 subjects by link-
study on hearing loss (9, 10) have clearly shown the age to population register information from Statistics
effects of self-reported occupational and impulse noise Norway. The data were matched on the basis of the
exposure on hearing. Detailed information on occupa- personal identification number given to all Norwegian
tion type was not provided in the previous analyses citizens. These identification numbers were removed
(9, 10). A recent set of analyses of a subsample of the before making the matched data material available to
Nord-Trøndelag study showed a negative relationship the researchers. In total, the sample consisted of 49 948
between occupational status and hearing loss (11). The subjects with complete data.
analyses in this paper are based on data from the total
Nord-Trøndelag study on hearing loss sample together
Measures
with information from the nationwide occupation regis-
ter administered by the governmental agency, Statistics Air conduction hearing thresholds were obtained by
Norway. Our primary aim was to determine the effects pure-tone audiometry at the following frequencies:
of specific types of occupation on hearing loss. We also 0.25, 0.5, 1, 2, 3, 4, 6, and 8 kHz. For details, please
examined the extent to which occupational differences in see Tambs et al (9). Two different pure-tone averages
hearing loss remained after adjustment for self-reported of permanent threshold shifts (PTS) were calculated:
occupational noise exposure, non-occupational noise (i) PTS3–4–6 (a binaural pure-tone average for frequencies
exposure, education, income, and other risk factors. of 3000 Hz, 4000 Hz, and 6000 Hz); and (ii) PTS0.5–1–2–4
(a pure-tone average for the better ear for frequencies
of 500, 1000, 2000, and 4000 Hz).
PTS3–4–6 reflects the frequency range that is most
Methods susceptible to noise-induced hearing loss. PTS0.5–1–2–4
identifies hearing loss in frequencies typical of normal
Study population conversational speech and is used to identify disabling
hearing loss. Disabling hearing loss was defined as a
The Nord-Trøndelag ���������������������������������
study on hearing loss is part of
������������������������ PTS0.5–1–2–4 of ≥35 dB hearing level. This criterion, which
the Nord-Trøndelag health study (HUNT). The entire deviates from the former WHO definition of ≥41 dB
adult population of Nord-Trøndelag County in Norway hearing level (12), is based on the new consensus agree-
was invited to participate in HUNT, which was con- ment by the recent Global Burden of Disease Hearing
ducted from January 1996 to February 1998. Screening Loss meeting, London, October 2008 (HJ Hoffman,
included several types of examinations; 17 of the 24 personal communication).
municipalities were offered hearing examinations, con- Occupation data were obtained using census records
sisting of pure-tone audiometry and two questionnaires, from 1970, 1980, and 1990. The most recent occupation
as part of the screening program. information was used. For example, if a subject was not
The subjects ranged in age from 20–101 years working in 1990, his or her occupation status from 1980
(median age 48.0 years; mean 50.2 ± 17.0 years). The was used. About 22% (14% of men and 30% of women)
participation rate for all municipalities together except were not working (ie, were occupationally inactive) at
one (Levanger) was 69%, 65% among men and 73% the time of any of the census registration years. Occupa-
among women. The corresponding rates for Levanger tion was coded according to the Nordic Classification
(in which the HUNT participants had to be re-invited of Occupations (13) using a 3-digit code. The digits
to have their hearing examined) were 42%, 39%, and represent the major class (“felt”), the sector (“område”),
45%, respectively. The participation rates varied with and the occupation group. The codes consist of 13, 86,
age, from around 40% for subjects <30 years or >80 and 412 groups, respectively (14).
Scand J Work Environ Health 2010, vol 36, no 3 251
3. Occupational hearing loss
Education data were available for 1980, 1985, 1990, We calculated the estimated marginal means of
1995, and 1998. We used the most recent education hearing thresholds (using SPSS with the UNIANOVA
information; education was classified into 10 levels. EMMEANS command) for each occupation group for
Income data from 1980, 1985, 1990, 1995, and 1998 men and woman, after adjusting for age, and compared
were obtained from the Norwegian Revenue Service these to the estimated marginal mean of the occupa-
and made available through Statistics Norway. Income tion group 064 (ie, “teachers – primary and vocational
was calculated as the mean income over the years avail- schools”). This group was chosen as a reference because
able, corrected for an increase in the general population of its low hearing thresholds and sufficient male and
income during the period 1980–1998. female subjects. The estimated marginal means of hear-
Self-reported noise exposure and other risk factors ing thresholds are simply referred to as the mean hearing
were obtained from the questionnaire data. Participants thresholds.
were asked to complete a one-page questionnaire We estimated the prevalence ratio for disabling
while in the waiting room prior to their audiometric hearing loss (PTS0.5–1–2–4 ≥35 dB) for each occupation
examination. using a log-binomial model with occupation group as
Occupational noise exposure was measured by ques- a factor and age as a covariate. The model, which is a
tionnaire items about loud noise at work in general generalized linear model in which the link function is
(scored 0–3) and specific noise from the following: the logarithm of the proportion under the study and the
staple gun/hammering, metal hammering/riveting, cir- distribution of the error is binomial, was estimated using
cular saw/machine planing, chainsaw operation, trac- the computer program R. Teachers were again used as
tor/construction machines, sledge hammer operation, the reference occupation. Direct estimates of prevalence
blasting, and machine-room and other factory noise. ratios by log-binomial regression have some advantages
(These items were scored using “yes” or “no”.) over odds ratios estimated with logistic regression
Non-occupational noise exposure was measured by analysis. Specifically, prevalence ratios are easier to
questionnaire items about impulse noise (ie, explosions, interpret, especially in strata with a high prevalence of
shootings); playing in a band or going to discotheques, hearing loss (17).
rock concerts, or similar loud events; recurrent ear infec-
tions (throughout the years); and hospitalization (ever)
for a head injury (these items were scored using “no”
= 0, “perhaps or I do not know” = 1, and “yes” = 2). Results
The items on the questionnaire are described in detail
elsewhere (15). Occupation had marked effects on hearing loss for the
two measures of hearing loss used (ie, PTS3–4–6 and
PTS0.5–1–2–4). The explained variances (adjusted R2) and
Statistical analysis
the effect of occupation, estimated as η2 ��������������
are shown for
We estimated the effects of occupation on hearing loss models with (i) age only, (ii) age and occupation, and
via multivariate analysis of variance (UNIANOVA (iii) controlling for self-reported noise exposure and
command) using the Statistical Package in the Social other socioeconomic and risk factors in tables 1 and 2.
Sciences (SPSS Inc, Chicago, IL, USA). Each of the Even though the age range was restricted for each
two hearing measures (ie, PTS3–4–6 and PTS0.5–1–2–4) were group, age effects were far stronger than those of occupa-
specified as dependent variables in consecutive analyses tion. Age accounted for 6–24% of the variance, depend-
entering age (in years) and occupation as fixed factors. ing upon age, gender, and PTS. Occupation additionally
The analyses were stratified by gender and age group explained 2–3% of the variance among men ≥45 years
(20–44 years, 45–64 years, and ≥65 years). Effect sizes and explained ≤1% of the variance among young men
were estimated as eta squared (η2), which was calcu- and women of all ages. For men, self-reported occupa-
lated as: tional noise explained up to 2.2% of the variance over
SSEffect and above occupation type. Other risk factors, educa-
η2 = (equation 1) tion, and income accounted for an additional ≤0.7% of
SST
the variance. While the effect of occupation was stronger
The SSEffect was the sum of the squares for occupation for PTS3–4–6 than PTS0.5–1–2–4 in most of the age stratified
and the SST was the total (corrected) sum of the squares groups, it was similar when the age groups were pooled.
(16). Changes in the effect of occupation after control- The effect of occupation (estimated as η2)���������������
was 0.05–0.07
ling for self-reported noise exposure, and socioeconomic in men ≥45 years and was reduced 20–40% by control-
and other risk factors were estimated as changes in η2 ling for self-reported occupational noise exposure. In
after subsequently entering additional control variables contrast, occupation effects hardly reduced at all the
��������������������������������������������� ����
in the model. already small effect of occupation among women.
252 Scand J Work Environ Health 2010, vol 36, no 3
4. Engdahl & Tambs
Table 1. Multivariate analysis of variance (ANOVA). Explained variance (adjusted R2) and effects of occupation [eta squared (h2)] among
men. (PTS3–4–6 = binaural pure-tone average for the frequencies of 3000, 4000, and 6000 Hz; PTS0.5–1–2–4 = pure-tone average of the better
ear for the frequencies of 500, 1000, 2000, and 4000 Hz)
Age group
Pure tone Model variables
average
Age Age and Age, occupation Age Age, occupation,
occupation and occupational occupation, all risk factors,a education,
noise exposure all risk factors a and income
Adjusted Adjusted h2 Adjusted h2 Adjusted h2 Adjusted h2
R2 (%) R2 (%) R2 (%) R2 (%) R2 (%)
20–44 years PTS3–4–6 11.8 13.0 0.037 13.7 0.033 15.1 0.031 15.5 0.028
PTS0.5–1–2–4 7.7 8.1 0.031 8.6 0.028 9.6 0.027 10.2 0.025
45–64 years PTS3–4–6 19.1 21.6 0.051 23.6 0.030 26.1 0.029 26.4 0.026
PTS0.5–1–2–4 14.6 16.9 0.050 18.7 0.033 20.4 0.033 21.0 0.029
>64 years PTS3–4–6 10.2 13.4 0.073 16.0 0.052 18.2 0.050 18.3 0.045
PTS0.5–1–2–4 16.9 19.8 0.067 22.0 0.051 23.7 0.051 23.9 0.045
All ages PTS3–4–6 60.0 61.0 0.016 61.8 0.009 62.7 0.009 62.8 0.007
PTS0.5–1–2–4 55.1 56.1 0.016 56.8 0.010 57.4 0.010 57.6 0.008
a Self-reported occupational noise, leisure noise, recurrent ear infections, and head injuries.
Table 2. Multivariate analysis of variance (ANOVA). Explained variance (adjusted R2) and effects of occupation �������������� 2)]�������
[eta squared (h among
women. (PTS3–4–6 = binaural pure-tone average for the frequencies of 3000, 4000, and 6000 Hz; PTS0.5–1–2–4 = pure-tone average of the
better ear for the frequencies of 500, 1000, 2000, and 4000 Hz)
Age group Pure tone Model variables
average
Age Age and Age, occupation Age Age, occupation,
occupation and occupational occupation, all risk factors,a education,
noise exposure all risk factors a and income
Adjusted Adjusted h2 Adjusted h2 Adjusted h2 Adjusted h2
R2 (%) R2 (%) R2 (%) R2 (%) R2 (%)
20–44 years PTS3–4–6 6.9 7.2 0.021 7.2 0.021 8.3 0.020 9.0 0.018
PTS0.5–1–2–4 5.5 5.8 0.021 5.8 0.021 6.9 0.020 7.6 0.018
45–64 years PTS3–4–6 12.8 14.0 0.031 14.2 0.029 15.2 0.029 15.3 0.024
PTS0.5–1–2–4 9.4 10.0 0.027 10.1 0.026 11.1 0.025 11.4 0.021
>64 years PTS3–4–6 24.2 24.0 0.017 24.5 0.017 26.0 0.017 26.1 0.014
PTS0.5–1–2–4 23.4 23.3 0.018 23.7 0.018 25.3 0.017 25.4 0.015
All ages PTS3–4–6 59.0 59.1 0.005 59.2 0.005 59.7 0.005 59.8 0.004
PTS0.5–1–2–4 53.6 53.8 0.006 53.8 0.006 54.4 0.006 54.6 0.004
a Self-reported occupational noise, leisure noise, recurrent ear infections, and head injuries.
Additional controls for leisure-related noise, recur- with the highest hearing thresholds were wood work
rent ear infections, and head injuries did not change and mining, with about 11 dB elevated thresholds at
the effect of occupation. Controlling for education and 3000–6000 Hz compared to the reference group. Among
income further reduced the effect of occupation, by women, there were only a few occupation groups with
about 10% among men aged 45–64 years and about significant elevated hearing thresholds.
15–18% among women 45–64 years. The prevalence of disabling hearing loss (PTS0.5–1–2–4
The mean hearing thresholds for different occupation ≥35 dB) was 10.3%, 12.5%, and 8.4% among the general
groups in relation to those of primary and vocational population, men, and women, respectively. Age-adjusted
school teachers (adjusted for age) are shown in tables prevalence ratios were calculated for disabling hearing
3 and 4. The tables are limited to occupations with the loss for each occupation group (ie, the ratios expected if
highest hearing thresholds and occupation groups with the mean age in the occupation group were equal to that
>39 subjects. (For a complete list of occupation groups, of the whole population). Again, primary and vocational
please see the supplemental material available on www. school teachers (prevalence among men 7.6% and woman
sjweh.fi/data_repository.php.) For men, the occupations 5.2%) were used as the reference group (tables 3 and 4).
Scand J Work Environ Health 2010, vol 36, no 3 253
5. Occupational hearing loss
Table 3. Predicted age-adjusted hearing threshold elevation (in dB) and adjusted prevalence ratio of PTS0.5–1–2–4 ≥35 dB among men a. Oc-
cupational groups were sorted by mean PTS3–4–6. The 31 groups with the highest means and >39 subjects are shown. (PTS3–4–6 = binaural
pure-tone average for frequencies of 3000, 4000, and 6000 Hz; PTS0.5–1–2–4 = pure-tone average of the better ear for frequencies of 500,
1000, 2000, and 4000 Hz; 95% CI = 95% confidence interval)
ratio
Nordic Classification of Occupational Codes PTS3–4–6 PTS0.5–1–2–4 Prevalence Sample
size
95% CI
Mean 95% CI ������������������
Mean��������������
95% CI ������
Mean��
(N=23 374)
77 Wood work 11.2 6.7–15.7 7.3 4.4–10.2 1.7 1.4–2.3 46
501 Miners – in underground mines, quarrymen, shot firers 10.9 8.4–13.3 5.7 4.1–7.3 1.8 1.4–2.4 171
765 Linemen & cable jointers 9.5 6.2–12.8 3.5 1.4–5.7 1.4 0.9–2.2 87
774 Construction carpenters & workers 9.2 7.9–10.5 5.6 4.7–6.4 1.6 1.3–2.1 911
612 Able & ordinary seamen 9.2 4.8–13.5 5.8 2.9–8.6 1.6 0.9–3.0 49
751 Workshop mechanics 8.5 6.2–10.9 4.3 2.8–5.9 1.1 0.7–1.8 183
753 Machine & motor repairmen 8.5 4.8–12.2 4.0 1.6–6.4 1.4 0.7–3.1 68
A30 Military – senior officers 8.2 4.1–12.2 3.8 1.2–6.4 1.5 0.9–2.5 58
876 Oilers and greasers etc 8.1 4.0–12.1 3.6 1.0–6.2 1.1 0.5–2.6 57
871 Stationary engine operators 7.9 3.1–12.7 2.5 -0.6–5.6 1.1 0.5–2.1 40
791 Masons, bricklayers & plasterers 7.3 4.2–10.4 3.4 1.4–5.4 1.1 0.7–1.8 101
755 Plumbers & pipe fitters 7.3 5.2–9.3 4.2 2.9–5.5 1.8 1.2–2.7 256
757 Metal plate & steel structural workers 7.2 4.8–9.7 4.6 3.0–6.2 1.8 1.2–2.7 174
75 Iron & metalware work 7.1 4.1–10.1 3.1 1.1–5.0 1.6 1.1–2.3 106
759 Others in 75 iron and metalware work 7.1 3.0–11.2 6.0 3.3–8.6 1.0 0.4–2.6 56
754 Sheet-metal workers 6.9 4.5–9.3 3.7 2.2–5.3 1.1 0.6–1.9 177
441 Forestry workers & loggers 6.9 4.9–8.9 4.1 2.8–5.4 1.3 0.9–1.8 276
836 Papermakers 6.8 3.9–9.6 3.2 1.4–5.0 1.5 1.0–2.3 124
872 Crane & hoist operators, etc 6.5 2.3–10.7 4.1 1.4–6.8 1.5 0.8–3.1 53
772 Sawmill & planing mill workers 6.4 4.5–8.4 4.2 2.9–5.5 1.4 1.0–1.9 282
874 Operators of earth-moving & other construction machinery 6.4 4.7–8.2 3.3 2.2–4.5 1.2 0.8–1.7 383
826 Butchers, sausage makers etc. 6.2 3.6–8.7 3.3 1.6–4.9 1.2 0.7–2.0 157
793 Cement finishers, excavators, etc 6.1 4.6–7.7 4.0 2.9–5.0 1.5 1.1–1.9 509
752 Fitter-machinists 6.1 4.7–7.5 3.6 2.7–4.5 1.7 1.3–2.3 695
834 Mechanical pulp workers 6.0 1.9–10.0 4.3 1.7–6.9 1.7 1.2–2.4 57
A20 Non-commissioned officers & subalterns 5.9 3.4–8.4 3.3 1.7–4.9 1.9 1.4–2.7 164
777 Wood working machine setters & operators 5.8 3.3–8.3 4.9 3.3–6.6 1.6 1.2–2.2 159
0X6 Personnel specialists 5.5 1.2–9.8 2.7 -0.1–5.5 1.5 0.7–3.2 50
821 Millers 5.5 1.2–9.8 3.4 0.6–6.2 1.2 0.7–2.1 51
X Occupation not reported 5.3 4.2–6.4 3.7 3.0–4.5 1.7 1.3–2.1 3216
401 General farmers, livestock farmers – working on own behalf 5.3 4.3–6.3 3.1 2.4–3.7 1.4 1.1–1.8 2763
a In relation to the reference occupation group 064, “Teachers – primary and vocational schools.”
Discussion
The effects of occupational exposure were comparable
but somewhat weaker than those of self-reported exposure
Our results showed that occupation had moderate effects in previous analyses of data from the Nord-Trøndelag
on hearing loss. The effects of occupation on women’s study on hearing loss (9, 10). Controlling for self-reported
hearing were small, confirming previous reports that occupational noise exposure reduced the occupation group
women are exposed to less occupational noise and have effect among men from negligible values up to 2.1% of
smaller threshold shifts due to occupational noise expo- the total variance (PTS3–4–6, >64 years), but the effect of
sure (9). As expected, occupation had greater effects occupation generally did not change very much in any
on thresholds averaged at 3000–4000 Hz than those group after this adjustment. This indicates that there may
averaged at 500–4000 Hz. The effect of occupation on be important occupational risk factors for hearing loss
hearing loss was much greater in older than younger other than noise. Such factors might include whole-body
people, and the most obvious explanation is cumulative vibration, work-related diseases, and exposure to occupa-
noise exposure. However, vulnerability may increase tion-related toxins; these factors were not examined in
with age, and the results may also reflect societal trends the present study. Self-reported occupational noise is far
such as decreased occupational noise and improved ear from perfect in terms of validity; this certainly reduced
protection during the 20th century although the size of the extent to which the effect of occupation group could
such a trend might be questionable. be explained by occupational noise, however.
254 Scand J Work Environ Health 2010, vol 36, no 3
6. Engdahl & Tambs
Table 4. Predicted age-adjusted hearing threshold elevation (in dB) and adjusted prevalence ratio of PTS0.5–1–2–4 ≥35 dB among women a.
Occupational groups were sorted by mean PTS3–4–6. The 31 groups with the highest means and >39 subjects are shown. (PTS3–4–6 = binaural
pure-tone average for frequencies of 3000, 4000, and 6000 Hz. PTS0.5–1–2–4 = pure-tone average of the better ear for frequencies of 500,
1000, 2000, and 4000 Hz, 95% CI = 95% confidence interval)
Nordic classification of occupational codes PTS ratio
3–4–6 PTS0.5–1–2–4 Prevalence Sample
size
95% CI
Mean 95% CI ������������������������
Mean��������������������
95% CI ������������
Mean��������
(N=26 907)
822 Bakers & pastry cooks 5.7 2.1–9.3 4.1 1.4–6.8 1.1 0.6–1.8 45
04 Nursing care 3.8 1.6–6.1 2.0 0.3–3.7 0.9 0.6–1.4 120
003 Other engineers, engineer technicians, industrial designers 3.5 0.0–7.0 1.5 -1.1–4.2 1.6 0.2–11.5 48
681 Postmen 3.4 -0.3–7.2 1.2 -1.6–4.1 0.8 0.1–5.3 41
913 Kitchen assistants 3.3 2.0–4.6 2.4 1.4–3.4 1.1 0.8–1.5 404
41 Farm work & livestock work 3.3 0.1–6.5 1.5 -1.0–3.9 0.9 0.5–1.7 56
X Occupation not reported 2.8 2.1–3.5 2.2 1.7–2.6 1.0 0.8–1.3 7946
932 Char workers & cleaners 2.7 1.9–3.5 1.9 1.3–2.5 1.0 0.8–1.3 1888
049 Others in 04 (nursing care) 2.5 1.1–3.9 2.0 1.0–3.1 1.3 0.9–1.8 355
915 Housekeepers – public service 2.5 1.4–3.5 1.6 0.8–2.3 1.0 0.8–1.2 842
912 Cooks 2.5 0.8–4.1 1.7 0.5–3.0 0.9 0.7–1.3 247
921 Headwaiters, waiters 2.4 0.9–3.9 1.8 0.7–2.9 1.2 0.9–1.6 295
825 Canning & other preservation workers 2.4 -0.4–5.1 2.2 0.1–4.2 1.3 0.6–2.7 80
411 Farm helpers – general 2.3 1.3–3.3 1.3 0.6–2.1 1.0 0.8–1.3 843
914 Housekeepers, maids – private service 1.8 0.0–3.5 1.2 -0.1–2.5 0.9 0.6–1.4 212
716 Sewers & embroiderers – textile products, leather garments 1.7 -0.8–4.2 0.8 -1.1–2.7 0.8 0.4–1.5 94
412 Livestock workers – general 1.7 0.4–3.0 1.1 0.2–2.1 0.9 0.7–1.2 439
413 Nursery workers & gardeners 1.7 -0.7–4.1 1.5 -0.3–3.3 0.9 0.5–1.5 106
919 Others in 91 (public safety & protection work) 1.5 0.1–3.0 0.7 -0.4–1.8 0.6 0.2–1.5 310
922 Other waiting personnel 1.4 -0.7–3.6 1.1 -0.5–2.7 0.6 0.3–1.3 136
911 Housekeepers etc (not private or public service) 1.4 -0.8–3.6 1.3 -0.3–3.0 1.0 0.7–1.6 129
043 Practical nurses in psychiatric institutions 1.4 -1.6–4.4 -0.4 -2.7–1.8 0.5 0.1–3.0 67
047 Nursemaids in hospitals & other institutions 1.4 -0.9–3.6 1.0 -0.7–2.7 0.4 0.1–3.1 119
292 Bank clerks 1.3 -0.5–3.1 0.6 -0.7–1.9 0.6 0.1–2.2 202
203 Other cashiers 1.2 -0.7–3.1 0.5 -0.9–1.9 0.4 0.2–1.0 176
294 Clerks – public health insurance 1.0 -2.0–3.9 1.0 -1.3–3.2 1.5 0.6–3.4 68
111 Directors, managers & working proprietors 1.0 -2.7–4.7 -0.2 -3.0–2.5 0.6 0.2–1.6 42
0X2 Social workers 1.0 -0.6–2.6 1.0 -0.2–2.2 0.6 0.3–1.4 263
951 Laundry & dry-cleaning workers 1.0 -1.7–3.7 0.4 -1.6–2.4 0.8 0.4–1.4 81
861 Packers, labelers & related workers 0.9 -1.4–3.2 1.3 -0.4–3.1 0.8 0.5–1.5 111
853 Plastic product makers 0.9 -1.5–3.3 0.6 -1.2–2.4 0.4 0.1–1.4 102
a In relation to the reference occupation group 064, “Teachers – primary and vocational schools.”
Other risk factors, such as noise during leisure activi- threshold elevation ranged from 7–11 dB at 3–6 kHz for
ties, recurrent ear infections, and head injuries have been the 20 occupations with the greatest effects on hearing
demonstrated to predict hearing loss and may well have loss; this was comparable to the 8–9 dB high-frequency
some relation to occupation. Nevertheless, controlling loss reported in the Nord-Trøndelag study on hearing
for these factors did not change the effect of occupa- loss for the upper 10th percentile of men >44 years with
tion on hearing loss in our study. However, controlling self-reported occupational noise exposure (9).
for education and income slightly reduced the effect of Only a few previous studies have reported occu-
occupation, consistent with previous results showing a pation-specific prevalence ratios. A German study of
social gradient for both increased mortality and morbid- 4958 construction workers estimated an age-adjusted
ity (18) and hearing loss (19–21). This result may reflect prevalence ratio for hearing loss of about 1.5 for blue-
moderate effects of confounders associated with social versus white-collar workers (22). In that study, hearing
background other than those observed in our study, such loss was defined as the sum of hearing thresholds at
as risky health behaviour. 2000, 3000, and 4000 Hz >105 dB in the worse ear.
For men, the most elevated hearing thresholds were The reported specific estimated ratios for carpenters,
found among: wood workers; miners; linemen and cable unskilled workers, bricklayers, plumbers, and plaster-
jointers; construction workers and carpenters; seamen; ers were 1.8, 1.8, 1.6, 1.5, and 1.3, respectively. These
and workshop mechanics. The magnitude of the hearing results are relatively consistent with our prevalence
Scand J Work Environ Health 2010, vol 36, no 3 255
7. Occupational hearing loss
ratios for disabling hearing loss (PTS0.5–1–2–4 ≥35 dB), category may have been preferable. There may be some
namely 1.6 for construction carpenters and workers and concern that noise levels at primary schools are harmful
1.8 for plumbers (versus teachers). We also found sig- to hearing although daily levels are reported mostly to be
nificantly elevated mean hearing thresholds for masons, ≤70 dB and only occasionally to be >80 dB (25).
bricklayers, and plasterers, although the prevalence ratio A weakness of the study was the lack of information
for disabling hearing was not significant. about the length of employment or duration of exposure.
The prevalence of hearing loss was determined for However, the estimated average hearing losses for each
13 519 sheet metal workers and 18 397 office workers occupation group apply to workers whose age is equal
in the Swedish construction industry in the period 1971– to the sample mean. Accordingly, we have essentially
1980 (23). The reported prevalence data gave prevalence adjusted for exposure duration. In addition, there is
ratios of 2.6 and 1.4 for workers aged 35–39 and 55–59 relatively high occupational stability in Nord-Trøndelag
years, respectively, for hearing loss at 4000 Hz >30 dB. County: 86% of the men and 97% of the women reported
The corresponding prevalence ratios at 500 Hz were 2.9 to have had ≤2 types of work that lasted >2 years (9).
and 1.7, respectively. Controlling for having had several types of work does
A study of the elderly in Wisconsin, USA, found not significantly change the estimated effects of occupa-
an increased risk of hearing loss for people working in tion reported in tables 1 and 2.
service, production, and operation occupations com- The Nordic Classification of Occupations does not
pared to those in management positions; the age- and classify occupations on the basis of noise-exposure levels
gender-adjusted odds ratios were 1.8, 3.5, and 2.0, or other risk factors for hearing loss, but according to the
respectively. Hearing loss was defined as an average tasks and duties undertaken in the job. Heterogeneity
hearing threshold at 500–4000 Hz that was >25 dB for regarding noise and other exposure within occupational
the worse ear (21). categories implies that occupation as an explanatory
In a recent analysis of self-reported hearing dif- variable does not capture all effects of occupational
ficulties in 130 102 employed respondents to the US exposure on hearing loss. Our results showed that adding
National Health Interview Survey, the industries with information on self-reported occupational noise exposure
the greatest prevalence ratios were: railroads; mining; improved the prediction of hearing loss somewhat.
primary metal manufacturing; and furniture, lumber, Selection for good hearing in some occupations could
and wood manufacturing with prevalence ratios of 2.7, in principle bias the results, but we think it unlikely that
2.2, 2.0, and 1.8, respectively. Employees in the finance, this type of selection had much effect on the results.
insurance, and real estate industries were used as a refer-
ence group, and the prevalence ratios were adjusted for
Concluding remarks
age, gender, race, smoking status, and education (24).
The prevalence ratio in the construction industry was This study found a moderate association between occu-
moderate (ie, 1.4), but construction still had the highest pation and hearing loss. Unbiased estimates of occupa-
number of persons with hearing difficulties that were tional hearing loss may help identify high-risk occupa-
attributable to employment. tions, in which interventions are needed.
Strengths and limitations
The major advantages of our study were its prospective Acknowledgements
design and the fact that its population was representative
of the general working population. Since occupation data This work was supported by the National Institute on
were complete for all participants, and the participation Deafness and Other Communication Disorders and by
rate in the population survey was relatively high (67% the National Institute of Health (research contract No
for the vast majority of the county), a substantial selec- N01–DC–6–2104).
tion bias is unlikely. The occupation data were obtained
from highly valid registry data, and the audiometric data
were equally reliable (9); thus, we consider recall bias
or other reporting bias to be minimal. References
The mean hearing thresholds in each occupation were
related to the mean of the teachers at primary and voca- 1. Davis AC. Epidemiology of hearing disorders. In: Kerr
tional schools. The rationale for choosing this group as AG, editor. Scott Brown´s otolaryngology. Boston (MA):
the reference was to choose a group of sufficient size to Butterworth-Heineman; 1997.
make the estimation of prevalence ratios as precise as pos- 2. Mathers CD, Stein C, Fat DM, Rao C, Inoue M, Tomijima N,
sible. Substantively, a completely non-exposed reference et al. Global burden of disease 2000: version 2 methods and
256 Scand J Work Environ Health 2010, vol 36, no 3
8. Engdahl & Tambs
results. Geneva: World Health Organization; 2002. Global of the comparable files. Oslo: Statistics Norway; 1987. Report
Programme on Evidence for Health Policy Discussion Paper Number 87/2.
Number 50
15. Engdahl B, Tambs K, Borchgrevink HM, Hoffman HJ.
3. European Agency for Safety and Health at Work. Noise in Screened and unscreened hearing threshold levels for the adult
figures. Luxembourg: Office for Official Publications of the population: results from the Nord-Trøndelag Hearing Loss
European Communities; 2005. Study. Int J Audiol. 2005;44(4):213–30.
4. World Health Organization (WHO). The world health report: 16. Cohen J. Eta-squared and partial eta-squared in fixed factor
reducing risks, promoting healthy life. Geneva; WHO; 2002. ANOVA designs. Educ Psychol Meas. 1973;33:107–12.
5. Nelson DI, Nelson RY, Concha-Barrientos M, Fingerhut M. 17. Barros AJ, Hirakata VN. Alternatives for logistic regression
The global burden of occupational noise-induced hearing loss. in cross-sectional studies: an empirical comparison of models
Am J Ind Med. 2005;48(6):446–58. that directly estimate the prevalence ratio. BMC Med Res
Methodol. 2003;3:21.
6. National Institute of Occupational Safety and Health
(NIOSH). Criteria for a recommended standard: occupational 18. Mackenbach JP, Kunst AE, Cavelaars AE, Groenhof F, Geurts
noise exposure: revised criteria 1998. Cincinnati (OH): US JJ. Socioeconomic inequalities in morbidity and mortality in
Department of health and human services; 1998. DHHS western Europe: the EU Working Group on Socioeconomic
(NIOSH) Publication Number 98–126. Inequalities in Health. Lancet. 1997;349(9066):1655–9.
7. European Agency for Safety and Health at Work. Data 19. Ries PW. Hearing ability of persons by sociodemographic
to describe the link between OSH and employability. and health characteristics: United States. Vital Health Stat 10.
Luxembourg: Office for Official Publications of the European 1982;10(140):1–60.
Communities; 2002.
20. Ries PW. Prevalence and characteristics of persons with
8. Swedish Work Environment Authority. Occupational accidents hearing trouble: United States, 1990–91. Vital Health Stat 10.
and work-related diseases 2005. Stockholm: Swedish Work 1994;(188):1–75.
Environment Authority; 2007. Arbetsmiljö statistik, report 21. Cruickshanks KJ, Wiley TL, Tweed TS, Klein BE, Klein
number 2007:2. R, Mares-Perlman JA, et al. Prevalence of hearing loss in
9. Tambs K, Hoffman HJ, Borchgrevink HM, Holmen J, older adults in Beaver Dam, Wisconsin: the Epidemiology of
Samuelsen SO. Hearing loss induced by noise, ear infections, Hearing Loss Study. Am J Epidemiol. 1998;148(9):879–86.
and head injuries: results from the Nord-Trøndelag Hearing 22. Arndt V, Rothenbacher D, Brenner H, Fraisse E, Zschenderlein
Loss Study. Int J Audiol. 2003;42(2):89–105. B, Daniel U, et al. Older workers in the construction industry:
10. Tambs K, Hoffman HJ, Borchgrevink HM, Holmen J, Engdahl results of a routine health examination and a five year follow
B. Hearing loss induced by occupational and impulse noise: up. Occup Environ Med. 1996;53(10):686–91.
results on threshold shifts by frequencies, age and gender 23. Schneider S, Johanning E, Belard JL, Engholm G. Noise,
from the Nord-Trøndelag Hearing Loss Study. Int J Audiol. vibration, and heat and cold. Occup Med. 1995;10(2):363–
2006;45(5):309–17. 83.
11. Helvik AS, Krokstad S, Tambs K. Socioeconomic inequalities 24. Tak S, Calvert GM. Hearing difficulty attributable to
in hearing loss in a healthy population sample: The HUNT employment by industry and occupation: an analysis of the
Study. Am J Public Health. 2009;99(8):1376–8. National Health Interview Survey – United States, 1997 to
2003. J Occup Environ Med. 2008;50(1):46–56.
12. Concha-Barrientos M, Campbell-Lendrum D, Steenland K.
Occupational noise: assessing the burden of disease from 25. Walinder R, Gunnarsson K, Runeson R, Smedje G.
work-related hearing impairment at national and local levels. Physiological and psychological stress reactions in relation
Geneva: World Health Organization; 2004. Report Number 9. to classroom noise. Scand J Work Environ Health.
2007;33(4):260–6.
13. Statistics Norway. Nordic Classification of Occupations. Oslo:
Statistics Norway; 1976.
14. Vassenden K. Censuses 1960, 1970 and 1980: documentation Received for publication: 10 July 2009
Scand J Work Environ Health 2010, vol 36, no 3 257