SlideShare a Scribd company logo

Acoustics Module 4_students.pdf

Z
zaindeen6

acoustics in building services

1 of 49
Download to read offline
BUILDING SERVICES IV ACOUSTICS & NOISE CONTROL - 18 ARC 7.3
MODULE 4 – NOISE REDUCTION AND CONTROL
18 ARC 7.3 BS IV
The World Health Organization (WHO) defines environmental noise as noise from all sources with the exception
of workplace noise. Noise is all unwanted sound or set of sounds that causes annoyance or can have a health
impact.
Environmental noise is the noise produced by
● Transport
● Industrial activities
● Construction site activities
● Public works and services
● Cultural, sporting and leisure activities
● Neighbourhood noise - Indoor and Outdoor
18 ARC 7.3 BS IV
NOISE CLASSIFICATION
● Outdoor and Indoor Noise
Noise from outdoor noise producing equipments like gardening
equipments etc or indoor noise like home appliances, fans, music
systems etc
● Airborne Noise
This type of noise is transmitted by air and atmosphere such as the
radio, the barking of dogs or people carrying on conversations.
When sound waves traveling through the air reach a building
element they hit it and cause it to vibrate. These vibrations travel
through the structure or building and are radiated out the other
side. Any loud music played in an adjacent building will feel like it
is reverberating within your building. This is due to airborne noise
traveling through windows and doors which are a major source of
sound leakage. Examples of Air borne noise are music and
television, conversation, traffic noise
18 ARC 7.3 BS IV
● Structure Borne Noise
Structure-borne noises are transmitted when sound arises from the
actual impact of an object on a building element such as a wall,
floor or ceiling. Example - footsteps on upper floors or stairs.
Structure-borne sound occurs because the impact causes both
sides of the building element to vibrate, generating sound waves.
This can often be the hardest to isolate.
STEPS TO REDUCE AIR BORNE AND STRUCTURE BORNE SOUND
● The best way to stop sound is having mass, an air gap and mass
again. Sound waves have a difficult time penetrating through
that space and continuing indoors.
● DGU for windows are costly but not very effective for sound
compared to thermal insulation. Double pane windows have an
average STC rating of about 26.
● Sound travels through flanking through doors and windows - air
and sound follow the same travel paths.
● Therefore weather stripping is used as added seal.
18 ARC 7.3 BS IV
● Impact Noise
Impact Noise is the physical impact on
buildings or solid materials. Examples being
footfall, doorsbanging, walking and furniture
moving.
Impact sound occurs because the impact
causes both sides of the building element to
vibrate, generating sound waves. This can
often be the hardest to isolate as impact
vibrations are stronger and travel further
through dense materials.
IMPACT NOISE Vs AIR BORNE NOISE
18 ARC 7.3 BS IV
● Noise from Mechanical systems like Ventilation system
and HVAC system
The vibrations from mechanical equipments in buildings -
(< 20 Hz) can be felt and heard by building occupants.
Vibrations along with noise can travel great distances
through building elements (structure borne noise)and may
be reradiated as air borne sound at a great distance from
the source.
Mechanical vibrating equipments should be placed on
resilient mounts to isolate the vibration from the building
structure.
Preferably vibrating equipments should be placed near
structural elements rather than on the md span of a slab.
● Community noise
Community noise is the environmental noise from all
sources except from the Industrial areas.

Recommended

Behavior of sound in enclosed spaces
Behavior of sound in enclosed spacesBehavior of sound in enclosed spaces
Behavior of sound in enclosed spacesR.Narasimha Swamy
 
Acoustics Material Study - Architectural Acoustics - NIT Trichy
Acoustics Material Study - Architectural Acoustics - NIT TrichyAcoustics Material Study - Architectural Acoustics - NIT Trichy
Acoustics Material Study - Architectural Acoustics - NIT TrichySabarathinam Kuppan
 
Architectural acoustics
Architectural acoustics Architectural acoustics
Architectural acoustics Geeva Chandana
 
Building service.ppt of neeru and aprajeeta
Building service.ppt of neeru and aprajeetaBuilding service.ppt of neeru and aprajeeta
Building service.ppt of neeru and aprajeetativar rose
 
Acoustics Module 5_students.pdf
Acoustics Module 5_students.pdfAcoustics Module 5_students.pdf
Acoustics Module 5_students.pdfzaindeen6
 

More Related Content

What's hot (20)

Architectural acoustic notes
Architectural acoustic notesArchitectural acoustic notes
Architectural acoustic notes
 
Some Acoustics Material
Some Acoustics MaterialSome Acoustics Material
Some Acoustics Material
 
Acoustic Materials & Specifications
Acoustic Materials & SpecificationsAcoustic Materials & Specifications
Acoustic Materials & Specifications
 
Room acoustics
Room acousticsRoom acoustics
Room acoustics
 
Acoustic material
Acoustic materialAcoustic material
Acoustic material
 
Acoustics buildings
Acoustics buildingsAcoustics buildings
Acoustics buildings
 
Case study on Apartment
Case study on ApartmentCase study on Apartment
Case study on Apartment
 
Partition wall
Partition wallPartition wall
Partition wall
 
Architectural acoustics
Architectural acousticsArchitectural acoustics
Architectural acoustics
 
Acoustics and design of movie theatre
Acoustics and design of movie theatreAcoustics and design of movie theatre
Acoustics and design of movie theatre
 
What are The Elements of Interior Design
What are The Elements of Interior Design What are The Elements of Interior Design
What are The Elements of Interior Design
 
Acoustic
Acoustic Acoustic
Acoustic
 
Neufert 3rd edition - Architect's Data
Neufert 3rd edition - Architect's DataNeufert 3rd edition - Architect's Data
Neufert 3rd edition - Architect's Data
 
Sound insulation of buildings(10 10-'15)
Sound insulation of buildings(10 10-'15)Sound insulation of buildings(10 10-'15)
Sound insulation of buildings(10 10-'15)
 
Architectural acoustics
Architectural acousticsArchitectural acoustics
Architectural acoustics
 
Case Study Report
Case Study ReportCase Study Report
Case Study Report
 
Acoustic materials
Acoustic materialsAcoustic materials
Acoustic materials
 
Acaustic
AcausticAcaustic
Acaustic
 
Panelling
PanellingPanelling
Panelling
 
Architectural acoustics
Architectural acousticsArchitectural acoustics
Architectural acoustics
 

Similar to Acoustics Module 4_students.pdf

Structure borne
Structure borneStructure borne
Structure borneYNam Ho
 
Acoustic Flooring Guide - Signature Floors NZ
Acoustic Flooring Guide - Signature Floors NZAcoustic Flooring Guide - Signature Floors NZ
Acoustic Flooring Guide - Signature Floors NZSignatureFloorsNZ
 
Acoustical and noise insulation
Acoustical and noise insulationAcoustical and noise insulation
Acoustical and noise insulationDhaval Jalalpara
 
NOISE CONTROL OF BUILDINGS
NOISE CONTROL OF BUILDINGSNOISE CONTROL OF BUILDINGS
NOISE CONTROL OF BUILDINGS sathish sak
 
Noise Control Stratagies in Reinforced Concrete Buildings
Noise Control Stratagies in Reinforced Concrete BuildingsNoise Control Stratagies in Reinforced Concrete Buildings
Noise Control Stratagies in Reinforced Concrete BuildingsIJRES Journal
 
Sound Control becomes more important every day.
Sound Control becomes more important every day.Sound Control becomes more important every day.
Sound Control becomes more important every day.Terry Cotton
 
Acoustical Design Considerations
Acoustical Design ConsiderationsAcoustical Design Considerations
Acoustical Design ConsiderationsIllinois ASHRAE
 
Sound insulation experiment
Sound insulation experimentSound insulation experiment
Sound insulation experimentRaymond Luk
 
Ultrasonic welding machine report BY saad izhar
Ultrasonic welding machine report  BY saad izharUltrasonic welding machine report  BY saad izhar
Ultrasonic welding machine report BY saad izharSaadIzhar
 
Building services
Building services Building services
Building services ssuserc0e35b
 
Jargon buster - sound insulation
Jargon buster - sound insulationJargon buster - sound insulation
Jargon buster - sound insulationSusan Witterick
 
acoustical defects in enclosed space
acoustical defects in enclosed spaceacoustical defects in enclosed space
acoustical defects in enclosed spaceEjas Halu Mohammed
 

Similar to Acoustics Module 4_students.pdf (20)

Structure borne
Structure borneStructure borne
Structure borne
 
Acoustic Flooring Guide - Signature Floors NZ
Acoustic Flooring Guide - Signature Floors NZAcoustic Flooring Guide - Signature Floors NZ
Acoustic Flooring Guide - Signature Floors NZ
 
AC2 M15.pdf
AC2 M15.pdfAC2 M15.pdf
AC2 M15.pdf
 
Noise acoustic
Noise  acousticNoise  acoustic
Noise acoustic
 
Acoustical and noise insulation
Acoustical and noise insulationAcoustical and noise insulation
Acoustical and noise insulation
 
NOISE CONTROL OF BUILDINGS
NOISE CONTROL OF BUILDINGSNOISE CONTROL OF BUILDINGS
NOISE CONTROL OF BUILDINGS
 
tl.ppt
tl.ppttl.ppt
tl.ppt
 
Noise Control Stratagies in Reinforced Concrete Buildings
Noise Control Stratagies in Reinforced Concrete BuildingsNoise Control Stratagies in Reinforced Concrete Buildings
Noise Control Stratagies in Reinforced Concrete Buildings
 
Sound Control becomes more important every day.
Sound Control becomes more important every day.Sound Control becomes more important every day.
Sound Control becomes more important every day.
 
Group 18
Group 18Group 18
Group 18
 
OSHA
OSHAOSHA
OSHA
 
Acoustical Design Considerations
Acoustical Design ConsiderationsAcoustical Design Considerations
Acoustical Design Considerations
 
LECTURE 3.pptx
LECTURE 3.pptxLECTURE 3.pptx
LECTURE 3.pptx
 
Noise control
Noise controlNoise control
Noise control
 
Sound insulation experiment
Sound insulation experimentSound insulation experiment
Sound insulation experiment
 
Ultrasonic welding machine report BY saad izhar
Ultrasonic welding machine report  BY saad izharUltrasonic welding machine report  BY saad izhar
Ultrasonic welding machine report BY saad izhar
 
Building services
Building services Building services
Building services
 
Jargon buster - sound insulation
Jargon buster - sound insulationJargon buster - sound insulation
Jargon buster - sound insulation
 
acoustical defects in enclosed space
acoustical defects in enclosed spaceacoustical defects in enclosed space
acoustical defects in enclosed space
 
Noise Pollution
Noise PollutionNoise Pollution
Noise Pollution
 

More from zaindeen6

site analysis, zoning and master plan.pdf
site analysis, zoning and master plan.pdfsite analysis, zoning and master plan.pdf
site analysis, zoning and master plan.pdfzaindeen6
 
construction equipments.pptx
construction equipments.pptxconstruction equipments.pptx
construction equipments.pptxzaindeen6
 
MMBC-8_REPORT_FUTURISTIC CITIES.pptx
MMBC-8_REPORT_FUTURISTIC CITIES.pptxMMBC-8_REPORT_FUTURISTIC CITIES.pptx
MMBC-8_REPORT_FUTURISTIC CITIES.pptxzaindeen6
 
SERVICES escalators.pptx
SERVICES escalators.pptxSERVICES escalators.pptx
SERVICES escalators.pptxzaindeen6
 
MMBC 3D PRINTING.pptx
MMBC 3D PRINTING.pptxMMBC 3D PRINTING.pptx
MMBC 3D PRINTING.pptxzaindeen6
 
climatron stl .ppt
climatron stl .pptclimatron stl .ppt
climatron stl .pptzaindeen6
 
GEOTHERMAL AIR CONDITIONING.pptx
GEOTHERMAL AIR CONDITIONING.pptxGEOTHERMAL AIR CONDITIONING.pptx
GEOTHERMAL AIR CONDITIONING.pptxzaindeen6
 

More from zaindeen6 (8)

CPM.pptx
CPM.pptxCPM.pptx
CPM.pptx
 
site analysis, zoning and master plan.pdf
site analysis, zoning and master plan.pdfsite analysis, zoning and master plan.pdf
site analysis, zoning and master plan.pdf
 
construction equipments.pptx
construction equipments.pptxconstruction equipments.pptx
construction equipments.pptx
 
MMBC-8_REPORT_FUTURISTIC CITIES.pptx
MMBC-8_REPORT_FUTURISTIC CITIES.pptxMMBC-8_REPORT_FUTURISTIC CITIES.pptx
MMBC-8_REPORT_FUTURISTIC CITIES.pptx
 
SERVICES escalators.pptx
SERVICES escalators.pptxSERVICES escalators.pptx
SERVICES escalators.pptx
 
MMBC 3D PRINTING.pptx
MMBC 3D PRINTING.pptxMMBC 3D PRINTING.pptx
MMBC 3D PRINTING.pptx
 
climatron stl .ppt
climatron stl .pptclimatron stl .ppt
climatron stl .ppt
 
GEOTHERMAL AIR CONDITIONING.pptx
GEOTHERMAL AIR CONDITIONING.pptxGEOTHERMAL AIR CONDITIONING.pptx
GEOTHERMAL AIR CONDITIONING.pptx
 

Recently uploaded

Spoleto Festival23 Hang and Cable Layouts.pdf
Spoleto Festival23 Hang and Cable Layouts.pdfSpoleto Festival23 Hang and Cable Layouts.pdf
Spoleto Festival23 Hang and Cable Layouts.pdfLizShek
 
creating my own logo and icon.pptx
creating my own logo and icon.pptxcreating my own logo and icon.pptx
creating my own logo and icon.pptxChloeMeadows1
 
Land Management and sourcing land for sustainable Urban Development.
Land Management and sourcing land for sustainable Urban Development.Land Management and sourcing land for sustainable Urban Development.
Land Management and sourcing land for sustainable Urban Development.JIT KUMAR GUPTA
 
Heathers Symbols for Gerald Freedman Theatre.pdf
Heathers Symbols for Gerald Freedman Theatre.pdfHeathers Symbols for Gerald Freedman Theatre.pdf
Heathers Symbols for Gerald Freedman Theatre.pdfLizShek
 
Studio Surfaced - Textile Design Studio based out of Delhi NCR
Studio Surfaced - Textile Design Studio based out of Delhi NCRStudio Surfaced - Textile Design Studio based out of Delhi NCR
Studio Surfaced - Textile Design Studio based out of Delhi NCRSurfaced - Designs By Meera Narula
 
PAGE ONE PAGE TWO PAGE THREE PAGE FOUR.pdf
PAGE ONE PAGE TWO PAGE THREE PAGE FOUR.pdfPAGE ONE PAGE TWO PAGE THREE PAGE FOUR.pdf
PAGE ONE PAGE TWO PAGE THREE PAGE FOUR.pdfssuser799b33
 
impact of packaging on consumer buying behaviour project report pdf.pdf
impact of packaging on consumer buying behaviour project  report pdf.pdfimpact of packaging on consumer buying behaviour project  report pdf.pdf
impact of packaging on consumer buying behaviour project report pdf.pdfSanjivanisShirodkar
 
homescreen revamp homescreen revamphomescreen revamp
homescreen revamp homescreen revamphomescreen revamphomescreen revamp homescreen revamphomescreen revamp
homescreen revamp homescreen revamphomescreen revampvidya934261
 
ASIF KHAN-LANDSCAPE-DESIGN PORTFOLIO 2024 f.pdf
ASIF KHAN-LANDSCAPE-DESIGN PORTFOLIO 2024 f.pdfASIF KHAN-LANDSCAPE-DESIGN PORTFOLIO 2024 f.pdf
ASIF KHAN-LANDSCAPE-DESIGN PORTFOLIO 2024 f.pdfaekhan1019
 
AWS-Architecture-Icons-Deck_For-Dark-BG_02062024.pptx
AWS-Architecture-Icons-Deck_For-Dark-BG_02062024.pptxAWS-Architecture-Icons-Deck_For-Dark-BG_02062024.pptx
AWS-Architecture-Icons-Deck_For-Dark-BG_02062024.pptxGopiNarahari1
 
Passing Strange Lighting Plot AS BUILT).pdf
Passing Strange Lighting Plot AS BUILT).pdfPassing Strange Lighting Plot AS BUILT).pdf
Passing Strange Lighting Plot AS BUILT).pdfLizShek
 
Presentation on "Gothic Architecher".pptx
Presentation on "Gothic Architecher".pptxPresentation on "Gothic Architecher".pptx
Presentation on "Gothic Architecher".pptxASHIQUR RAHMAN
 
Portfolio of designs and Visualization Samuel Jayeola
Portfolio of designs and Visualization Samuel JayeolaPortfolio of designs and Visualization Samuel Jayeola
Portfolio of designs and Visualization Samuel JayeolaJayeola Samuel
 
Mother Courage and Her Children Layouts.pdf
Mother Courage and Her Children Layouts.pdfMother Courage and Her Children Layouts.pdf
Mother Courage and Her Children Layouts.pdfLizShek
 
Gerald Freedman Theatre Rep Re-Circuit.pdf
Gerald Freedman Theatre Rep Re-Circuit.pdfGerald Freedman Theatre Rep Re-Circuit.pdf
Gerald Freedman Theatre Rep Re-Circuit.pdfLizShek
 
new Principle of design and the elements of design
new Principle of design and the elements of designnew Principle of design and the elements of design
new Principle of design and the elements of designbhamshu738
 
Mother Courage and Her Children Layouts.pdf
Mother Courage and Her Children Layouts.pdfMother Courage and Her Children Layouts.pdf
Mother Courage and Her Children Layouts.pdfLizShek
 
Preposition for grade 12th Vietnamese student
Preposition for grade 12th Vietnamese studentPreposition for grade 12th Vietnamese student
Preposition for grade 12th Vietnamese studentThaoNguyenDang4
 
Before and After Wheelchair Accessible Whole Home Remodel.pptx
Before and After Wheelchair Accessible Whole Home Remodel.pptxBefore and After Wheelchair Accessible Whole Home Remodel.pptx
Before and After Wheelchair Accessible Whole Home Remodel.pptxleahlareaupci
 

Recently uploaded (20)

Spoleto Festival23 Hang and Cable Layouts.pdf
Spoleto Festival23 Hang and Cable Layouts.pdfSpoleto Festival23 Hang and Cable Layouts.pdf
Spoleto Festival23 Hang and Cable Layouts.pdf
 
creating my own logo and icon.pptx
creating my own logo and icon.pptxcreating my own logo and icon.pptx
creating my own logo and icon.pptx
 
Maximize Your Brand Impact with a Box Truck Wrap Design
Maximize Your Brand Impact with a Box Truck Wrap DesignMaximize Your Brand Impact with a Box Truck Wrap Design
Maximize Your Brand Impact with a Box Truck Wrap Design
 
Land Management and sourcing land for sustainable Urban Development.
Land Management and sourcing land for sustainable Urban Development.Land Management and sourcing land for sustainable Urban Development.
Land Management and sourcing land for sustainable Urban Development.
 
Heathers Symbols for Gerald Freedman Theatre.pdf
Heathers Symbols for Gerald Freedman Theatre.pdfHeathers Symbols for Gerald Freedman Theatre.pdf
Heathers Symbols for Gerald Freedman Theatre.pdf
 
Studio Surfaced - Textile Design Studio based out of Delhi NCR
Studio Surfaced - Textile Design Studio based out of Delhi NCRStudio Surfaced - Textile Design Studio based out of Delhi NCR
Studio Surfaced - Textile Design Studio based out of Delhi NCR
 
PAGE ONE PAGE TWO PAGE THREE PAGE FOUR.pdf
PAGE ONE PAGE TWO PAGE THREE PAGE FOUR.pdfPAGE ONE PAGE TWO PAGE THREE PAGE FOUR.pdf
PAGE ONE PAGE TWO PAGE THREE PAGE FOUR.pdf
 
impact of packaging on consumer buying behaviour project report pdf.pdf
impact of packaging on consumer buying behaviour project  report pdf.pdfimpact of packaging on consumer buying behaviour project  report pdf.pdf
impact of packaging on consumer buying behaviour project report pdf.pdf
 
homescreen revamp homescreen revamphomescreen revamp
homescreen revamp homescreen revamphomescreen revamphomescreen revamp homescreen revamphomescreen revamp
homescreen revamp homescreen revamphomescreen revamp
 
ASIF KHAN-LANDSCAPE-DESIGN PORTFOLIO 2024 f.pdf
ASIF KHAN-LANDSCAPE-DESIGN PORTFOLIO 2024 f.pdfASIF KHAN-LANDSCAPE-DESIGN PORTFOLIO 2024 f.pdf
ASIF KHAN-LANDSCAPE-DESIGN PORTFOLIO 2024 f.pdf
 
AWS-Architecture-Icons-Deck_For-Dark-BG_02062024.pptx
AWS-Architecture-Icons-Deck_For-Dark-BG_02062024.pptxAWS-Architecture-Icons-Deck_For-Dark-BG_02062024.pptx
AWS-Architecture-Icons-Deck_For-Dark-BG_02062024.pptx
 
Passing Strange Lighting Plot AS BUILT).pdf
Passing Strange Lighting Plot AS BUILT).pdfPassing Strange Lighting Plot AS BUILT).pdf
Passing Strange Lighting Plot AS BUILT).pdf
 
Presentation on "Gothic Architecher".pptx
Presentation on "Gothic Architecher".pptxPresentation on "Gothic Architecher".pptx
Presentation on "Gothic Architecher".pptx
 
Portfolio of designs and Visualization Samuel Jayeola
Portfolio of designs and Visualization Samuel JayeolaPortfolio of designs and Visualization Samuel Jayeola
Portfolio of designs and Visualization Samuel Jayeola
 
Mother Courage and Her Children Layouts.pdf
Mother Courage and Her Children Layouts.pdfMother Courage and Her Children Layouts.pdf
Mother Courage and Her Children Layouts.pdf
 
Gerald Freedman Theatre Rep Re-Circuit.pdf
Gerald Freedman Theatre Rep Re-Circuit.pdfGerald Freedman Theatre Rep Re-Circuit.pdf
Gerald Freedman Theatre Rep Re-Circuit.pdf
 
new Principle of design and the elements of design
new Principle of design and the elements of designnew Principle of design and the elements of design
new Principle of design and the elements of design
 
Mother Courage and Her Children Layouts.pdf
Mother Courage and Her Children Layouts.pdfMother Courage and Her Children Layouts.pdf
Mother Courage and Her Children Layouts.pdf
 
Preposition for grade 12th Vietnamese student
Preposition for grade 12th Vietnamese studentPreposition for grade 12th Vietnamese student
Preposition for grade 12th Vietnamese student
 
Before and After Wheelchair Accessible Whole Home Remodel.pptx
Before and After Wheelchair Accessible Whole Home Remodel.pptxBefore and After Wheelchair Accessible Whole Home Remodel.pptx
Before and After Wheelchair Accessible Whole Home Remodel.pptx
 

Acoustics Module 4_students.pdf

  • 1. BUILDING SERVICES IV ACOUSTICS & NOISE CONTROL - 18 ARC 7.3 MODULE 4 – NOISE REDUCTION AND CONTROL
  • 2. 18 ARC 7.3 BS IV The World Health Organization (WHO) defines environmental noise as noise from all sources with the exception of workplace noise. Noise is all unwanted sound or set of sounds that causes annoyance or can have a health impact. Environmental noise is the noise produced by ● Transport ● Industrial activities ● Construction site activities ● Public works and services ● Cultural, sporting and leisure activities ● Neighbourhood noise - Indoor and Outdoor
  • 3. 18 ARC 7.3 BS IV NOISE CLASSIFICATION ● Outdoor and Indoor Noise Noise from outdoor noise producing equipments like gardening equipments etc or indoor noise like home appliances, fans, music systems etc ● Airborne Noise This type of noise is transmitted by air and atmosphere such as the radio, the barking of dogs or people carrying on conversations. When sound waves traveling through the air reach a building element they hit it and cause it to vibrate. These vibrations travel through the structure or building and are radiated out the other side. Any loud music played in an adjacent building will feel like it is reverberating within your building. This is due to airborne noise traveling through windows and doors which are a major source of sound leakage. Examples of Air borne noise are music and television, conversation, traffic noise
  • 4. 18 ARC 7.3 BS IV ● Structure Borne Noise Structure-borne noises are transmitted when sound arises from the actual impact of an object on a building element such as a wall, floor or ceiling. Example - footsteps on upper floors or stairs. Structure-borne sound occurs because the impact causes both sides of the building element to vibrate, generating sound waves. This can often be the hardest to isolate. STEPS TO REDUCE AIR BORNE AND STRUCTURE BORNE SOUND ● The best way to stop sound is having mass, an air gap and mass again. Sound waves have a difficult time penetrating through that space and continuing indoors. ● DGU for windows are costly but not very effective for sound compared to thermal insulation. Double pane windows have an average STC rating of about 26. ● Sound travels through flanking through doors and windows - air and sound follow the same travel paths. ● Therefore weather stripping is used as added seal.
  • 5. 18 ARC 7.3 BS IV ● Impact Noise Impact Noise is the physical impact on buildings or solid materials. Examples being footfall, doorsbanging, walking and furniture moving. Impact sound occurs because the impact causes both sides of the building element to vibrate, generating sound waves. This can often be the hardest to isolate as impact vibrations are stronger and travel further through dense materials. IMPACT NOISE Vs AIR BORNE NOISE
  • 6. 18 ARC 7.3 BS IV ● Noise from Mechanical systems like Ventilation system and HVAC system The vibrations from mechanical equipments in buildings - (< 20 Hz) can be felt and heard by building occupants. Vibrations along with noise can travel great distances through building elements (structure borne noise)and may be reradiated as air borne sound at a great distance from the source. Mechanical vibrating equipments should be placed on resilient mounts to isolate the vibration from the building structure. Preferably vibrating equipments should be placed near structural elements rather than on the md span of a slab. ● Community noise Community noise is the environmental noise from all sources except from the Industrial areas.
  • 7. 18 ARC 7.3 BS IV ● Construction noise The noise generated at construction sites due to construction activities like rock breaking, machinery working, welding , metal cutting etc. These need to be properly regulated so that it does not affect the residents around a construction site. ● Industrial noise The noise generated by machinery and equipments in an Industrial setting is classified as industrial noise. It can affect the auditory sensibilities of people working in such a setting. These are occupational hazards.
  • 8. 18 ARC 7.3 BS IV NOISE TRANSMISSION Transmission loss (TL) is measured in dB. It is a measure of how much sound energy is reduced in transmission through materials. The more massive a material, higher is the TL. However in addition to the weight, other factors also affect the TL. For E.g certain natural frequencies for bending waves can exist depending on the stiffness of the construction. When such waves are excited by sound energy impinging on them , the resistance to sound transmissions are greatly reduced (a phenomenon called coincidence effect). Transmission loss of sound is a measurement of the reduction in sound level of a sound source as it passes through an acoustic barrier. It is the number of decibels that are stopped by the acoustical barrier or the wall and is measured at different frequencies. TRANSMISSION LOSS is a measurement of the dB (volume) difference on either side of a wall.
  • 9. 18 ARC 7.3 BS IV Transmission Loss can be expressed as TL = L1 - L2 Where TL= Transmission Loss (dB) L1 = Sound level in Lab Source room (dB) L2= Sound level in Lab Receiving room (dB) And TL = 10log 1/τ Where TL = Transmission Loss (dB) τ= sound transmission coefficient (no units) τ (tau) is the ratio of the sound energy transmitted by a material to the incident sound energy.
  • 10. 18 ARC 7.3 BS IV What is STC (Sound Transmission Class) rating in Acoustics ? Sound Transmission Class (STC ) is an integer rating of how well a building partition (partition assembly) attenuates airborne sound. It is widely used to rate interior partitions, ceilings and floors, doors, windows and exterior wall configurations (see ASTM International Classification E413 and E90). STC is considered for an assembly and not for a particular material. STC is calculated by taking the Transmission Loss (TL) values tested at 16 standard frequencies over the range of 125 Hz to 4000 Hz and plotted on a graph. Note: STC only considers frequencies down to 125Hz and can be misleading since sound isolation complaints are mostly from sources below 125Hz
  • 11. 18 ARC 7.3 BS IV ● STC rating - how much sound is blocked from going through a product ● NRC Rating - how much sound is absorbed by a product. ● The STC rating is important when trying to reduce the amount of sound entering or leaving a room. ● The NRC rating is important when trying to reduce echo and improve the sound quality in a room. ● STC rating for walls may be different from the acceptable STC rating for floors. The higher the rating, the more sound is blocked from going through the material. With a Sound transmission class rating of 50, speech cannot be heard through the walls, and loud sounds are only faintly audible.
  • 12. 18 ARC 7.3 BS IV STC What can be heard at this level 25 Soft speech can be heard and understood 30 Normal speech can be heard and understood 35 Loud speech can be heard and understood 40 Loud speech can be heard, but not understood 45 The threshold at which privacy begins 50 Loud sounds can be heard, but are very faint 60+ At this level, good soundproofing begins. Neighbors generally are not disturbed by very loud speech from inside. STC RATING CHART
  • 13. 18 ARC 7.3 BS IV An STC rating of 45 - get into the world of soundproofing and privacy. This could be considered a baseline when you are getting serious about preventing sound transmission. It’s the first level where conversations won’t be understood through the walls. The International Building Code requires an STC of 50 for multi family construction, which is the point at which noise is reduced to a point that people generally feel like their homes are adequately insulated from noise. The STC rating of walls has to do with multiple variables. Things like the thickness and air space within the wall can improve the rating greatly. Soundproofing - usually defined by weakest point. A high STC rating wall can be rendered ineffective by a hollow core door, or a single pane window. The STC rating works well for things like speech and the daily incidental sounds associated with living or working in a space, but isn’t incredibly accurate when evaluating music or heavy machinery, since those sounds live in lower frequencies, and will vibrate structures differently.
  • 14. 18 ARC 7.3 BS IV STC does not measure how many decibels a material can block STC ratings cannot be added together. STC ratings are calculated by measuring the transmission loss values of 16 - 18 different frequencies between 125 Hz and 4000 Hz and plotting those values as a curve on a graph. That curve is then compared to standard STC rating curves to determine a score. NOTE:
  • 15. 18 ARC 7.3 BS IV MASS LAW AND TRANSMISSION LOSS According to the Mass Law for homogeneous building materials like glass, wood , concrete, TL and sound transmission class rating (STC rating) increase by about 5 for each doubling of surface weight (in pounds per sqft). Sound Transmission Class (STC) system rates the entire TL curve at speech frequencies from 125Hz to 4000 Hz(frequency for speech range) using a standard contour as a reference. STC is a single number rating of TL performance for a construction element tested over standard frequencies as mentioned above. The higher the STC, the more efficient the construction is for reducing sound transmission. Heavier Materials provide better sound isolation - this is the fundamental principle of sound isolation for architectural acoustics.
  • 16. 18 ARC 7.3 BS IV Mass law follows the law of diminishing returns. As seen in the adjacent figure , the STC of a homogeneous construction increases by approx 5 for each doubling of weight. Initial doubling provides the most practical improvement. Each successive doubling produces less STC improvement per unit weight and a greater increase in cost per unit STC increase. Therefore complex constructions are required when it is necessary to achieve high STC and TL improvements. Sound isolation also depends on the stiffness and mass of the materials
  • 17. 18 ARC 7.3 BS IV The sound isolation depends on the stiffness as well as mass The adjacent graph shows 2 plywoods of equivalent total weight. One has grooves the other is stiff. As per Mass Law the TL should be same. However the graph shows that the less stiff plywood (with grooves)has higher TL performance at the mid and high frequencies compared to the stiff one. Stiff panels are needed if high performance is required at low frequencies. The best barriers are heavy, high mass, limp, highly damped materials with a high weight to stiffness ratio such as our soundproofing mats.
  • 18. 18 ARC 7.3 BS IV The ideal sound isolating construction would be heavy, limp and airtight. Graph showing TL performance based on equal surface weight for several materials The graph has 3 basic parts ● The low frequency mass-controlled region at about 6dB per octave slope ● The plateau region of relatively constant TL which depends on bending stiffness and internal damping of the material ● And the Critical frequency and mass controlled region above the plateau usually at 10 dB octave slope. ● The stiffer the wall, lower the plateau height (poor sound isolating performance) ● Limper the material higher the plateau height ( better sound isolating performance) ● The more damping a wall has(energy loss from internal friction) the narrower the plateau width (better sound isolating performance)
  • 19. 18 ARC 7.3 BS IV A noise problem starts with a noise source such as a stream of traffic on a highway. The noise is transmitted through a path and then arrives at the receiver. The noise will be perceived as a problem when the noise is so high as to be a nuisance to the receiver. The severity of the problem depends on the strength of the noise source (such as heavy or light traffic) or the length of the path, that is, how large is the separation between the noise source and the receiver. DESIGN PRINCIPLES FOR NOISE MITIGATION To reduce environmental noise the following methods can be considered 1. Control at noise sources 2. Noise reduction at transmission path 3. Protection at receiver end.
  • 20. 18 ARC 7.3 BS IV Control at source ● Primary consideration is to reduce noise at source. ● The sound producing machinery or equipment may be enclosed in an acoustical enclosure to reduce the noise at source.A noise enclosure for reducing machine noise is commonly made of an exterior metal skin, an interior perforated sheet, with some absorptive materials such as fiberglass filled in between. ● Certain new and quieter technologies have enabled some construction works to be done much quieter as compared with conventional noisy equipment. For instance, some building demolition projects have adopted the more environmentally-friendly hydraulic crusher instead of the conventional mounted breaker. Noise reduction at transmission path ● Noise sources can be distanced from the receiver to mitigate noise. ● Obstruction through landscaping features like earth bund or screening with natural landscape or structures of noise tolerant uses (like carpark , commercial spaces, ) Protection at the receiver end ● Orientation of building and noise sensitive spaces ● Specification of materials to help mitigate noise effects like glazing and insulation for acoustic purpose.
  • 21. 18 ARC 7.3 BS IV POOR BETTER OUTDOOR BARRIERS FOR NOISE CONTROL
  • 22. 18 ARC 7.3 BS IV BEST
  • 23. 18 ARC 7.3 BS IV ● A self protecting building configuration - act as screens by interrupting the acoustic line of sight. ● Windows and doors are the weak point as it allows sound to travel. ● Self protecting building features are atriums, recessed floors and podium bases. ● Balconies and overhangs can be used to isolate surface traffic noise. ● Underside of the overhang can be treated with sound absorbing materials ● Solid balconies and overheads- reduce noise transmission by 5-10 dB.
  • 24. 18 ARC 7.3 BS IV
  • 25. 18 ARC 7.3 BS IV Sound leaks like water and travels through any small openings. So when sound isolation is required ● Seal cracks and open joints in partitions ● Avoid back to back electrical sockets ● Eliminate all potential sound leaks Sound Control - Enclosures and Barriers PARTITION LEAKS 2 layers of gypsum boards on steel studs
  • 26. 18 ARC 7.3 BS IV ELECTRICAL OUTLET LEAKS DOOR LEAKS An opening of 0.01% of wall surface area can reduce the TL from 50dB to 39dB.
  • 27. 18 ARC 7.3 BS IV When a weaker element like a door or window is used in a construction the composite TL for the combination is usually closer to the TL of the weaker element than to the stronger . Composite TL = 10 Log ΣS/ΣτS Where TL = Transmission Loss (dB) S = Surface Area (sqft) τ = Sound transmission coefficient (No units)
  • 28. 18 ARC 7.3 BS IV Combination of glass and brick walls and its effect on TL
  • 29. 18 ARC 7.3 BS IV NOISE REDUCTION NR BETWEEN ROOMS NR = L1 - L2 NR = Noise reduction (dB) L1= Sound level in source room (dB) L2= Sound level in receiving room (dB) NR at a given frequency is independent of the noise level in the source room. NR is dependent on 3 different factors ● Area of wall transmitting sound (S in sqft) ● Absorption in receiving room (a2 in Sabins) ● Transmission loss of common wall (TL in dB) NR = TL + 10Log a2/S Where TL= Sound transmission loss of common barrier a2= absorption in receiving room (Sabins) S = Surface area of common barrier (sqft) Note : 10Log a2/S may range between 6dB to - 6dB
  • 30. 18 ARC 7.3 BS IV Sound travels through indirect paths as shown in the adjacent pictures - that is called FLANKING. Poor workmanship can diminish the sound isolation and cause sound leaks
  • 31. 18 ARC 7.3 BS IV
  • 32. 18 ARC 7.3 BS IV ● The TL of a wall can be increased by separating the wall layers with airspace- to form double wall construction. ● TL increases with cavity air space. ● TL further increases with sound absorbing material added in the cavity air space. ● Double stud construction breaks direct sound transmission through studs. ● Further improvement with doubling the weight of gypsum on either side. DRY WALL CONSTRUCTION WITH WOODEN STUDS
  • 33. 18 ARC 7.3 BS IV ● Heavy Gypsum board construction on each side of studs, raises the STC level.Doubling the layer on either side of the studs can increase the STC by more than 5. ● Direct sound transmission path to be broken by staggering the wooden studs. ● Lightweight metal channel studs (25 gauge or lighter) provide higher STC values since they are less stiff than the wooden studs or heavy metal studs. ● Sound absorbing blankets to be placed in the cavity between the 2 studs which friction fit between studs with adequate fasteners so that they do not sag. ● Seal all cracks, joints and penetrations. Seal perimeters of bottom runners and sole plates with continuous beads of non hardening caulking at edges on each side. ● Isolate perimeters of common walls from ceilings, intersecting walls and structural members. Seal with caulking. ● Stagger electrical outlets by at least 2’-3’. Seal all the edges. ● Isolate plumbing from framing elements which act as sounding boards for noise of flowing water. DRY WALL CONSTRUCTION WITH METAL STUDS
  • 34. 18 ARC 7.3 BS IV COMPLEX MASONRY WALLS FOR SOUND INSULATION
  • 35. 18 ARC 7.3 BS IV Floated Floor concrete slab Wood Joist Floor FLOOR CEILING CONSTRUCTION ● To prevent squeaking floors in wood joist constructions - nails must be of proper size and spacing ● Install building paper or felt layer between sub floor and finished floor. ● Use seasoned wood. ● To prevent flanking - install joists parallel to the party walls. ● Cut sub flooring at walls(>¼ “ gap)to interrupt flanking path for airborne sound and vibrations. ● Ceiling should be an effective barrier to sound transmission from room to room as the common wall. ● The ceiling materials should be of increasing mass and decreasing porosity.
  • 36. 18 ARC 7.3 BS IV
  • 37. 18 ARC 7.3 BS IV PLENUM BARRIERS Gypsum board, lead sheet and mineral fiber can be used as vertical barriers to prevent flanking through ceiling plenums.
  • 38. 18 ARC 7.3 BS IV SOUND LOCK ● Stagger doors on opposite sides of double loaded corridors to prevent noise from travelling directly. ● Stub corridors or vestibules as sound locks.
  • 39. 18 ARC 7.3 BS IV SOUND INSULATION AND VIBRATION ISOLATION FROM MECHANICAL EQUIPMENT Poor isolation Better isolation
  • 40. 18 ARC 7.3 BS IV Vibration isolation - install vibrating equipment on resilient materials like ribbed or waffle shaped neoprene pads, pre compressed glass fibre pads and steel springs.
  • 41. 18 ARC 7.3 BS IV Both supply and return air duct should contain flexible canvas, rubber or loaded vinyl connections to break the vibration path.
  • 42. 18 ARC 7.3 BS IV
  • 43. 18 ARC 7.3 BS IV CHECKLIST FOR DUCT BORNE NOISE
  • 44. 18 ARC 7.3 BS IV
  • 45. 18 ARC 7.3 BS IV
  • 46. 18 ARC 7.3 BS IV
  • 47. 18 ARC 7.3 BS IV
  • 48. 18 ARC 7.3 BS IV
  • 49. 18 ARC 7.3 BS IV https://www.quebec.ca/en/health/advice-and-prevention/health-and-environment/the-effects-of-environmental-noise-on- health/definition-environmental-noise https://residential-acoustics.com/airborne-noise-vs-structure-borne-noise/ https://www.soundproofingstore.co.uk/whats-the-difference-between-impact-and-airborne-noise https://www.constructionspecifier.com/controlling-mechanical-system-noise/ https://ocw.upj.ac.id/files/Textbook-ARS-405-TEXTBOOK-13-FISIKA-BANGUNAN.pdf https://www.epd.gov.hk/epd/noise_education/web/text/ENG_EPD_HTML/m4/mitigation_1.html https://www.soundassured.com/blogs/blog/what-is-transmission-loss-of-sound https://amorimcorkcomposites.com/en/materials-applications/construction/knowledge-center/glossary/ https://www.acousticalsurfaces.com/blog/acoustics-education/sound-transmission-class-stc-rating/ https://www.soundproofingcompany.com/soundproofing_101/understanding-stc-and-stc-ratings https://www.secondskinaudio.com/sound-blocking/stc-rating/ http://www.domesticsoundproofing.co.uk/sound_transmission_loss.htm