Tarek Ghannoum , M.D. Audiology Unit , ENT DepartmentKasr Alainy Hospitals- Cairo University
Hearing loss :
Hearing loss:*Any degree of impairment of the ability to apprehend sound.*Being partly or totally unable to hear sound.
CHILD:*A person between birth and full growth.Infant:*A person not more than 12 months old.
Prevalence of Hearing Loss:* Prevalence estimates vary across studies.*Estimated that 1 to 3 per 1000 infants willhave permanent sensorineural hearingloss. -1/1000 from well baby nursery. -10/1000 from the NICU.* Rate increases to 6/1000by school age.
Children with hearing problems may have difficulties in:*Language and/or speech development.* Listening and understanding in noisyenvironments.*Paying attention and participation in noise(class).*Hearing differences between sounds in words.
Hearing loss:Impaired all brain functions:*Speech and language development.*Cognitive functions and intellectual abilities*Social activities.
Neurological Issues:We hear with the brain—the ears are just a way in. Children can’t listen like adults 1. The higher auditory brain centers are not fully developed (15 years). 2. Children cannot perform sophisticated automatic auditory cognitive closure.
SoInfants and children need: Quieter environment (S/N ratio) Louder signals than adult
Hearing loss is not about the ears, it’s about the brain.Any-time the word hearing is used, think about “auditory brain development”Acoustic accessibility of intelligible speech is essential for brain growth (CAP).Hearing is the first order event for the development of spoken communication and literacy skills.
Summary of NeuroplasticityGreatest in the first year of life.The younger the infant, the greater the neuroplasticity.Rapid brain growth requires prompt intervention, including amplification and habilitation programs.In the absence of sound, the brain re- organizes itself to receive input from other senses, primary vision- cross modal reorganization. This reduces auditory neural capacity
Goals for hearing screening:All infants must access hearing screening no later than 1 month of age.All confirmed cases should receive early intervention not later than 6 months of age.
ReminderA pass on newborn hearing screening does not guarantee typical hearing forever.High risk babies should undergo retesting every 6-12 months.Any child with delayed language development should be retested.Average age for identification of hearing loss is after 3 years of age.
Normal chart of language development:Cry (at birth)Pseudocry (2-3 weeks)Babling (3-4 months)Lalling (6 months)Echolalling (9 months)One word ( one year)Two words (2 years)Three words (3 years)Full language maturation (School age)
Degrees of hearing loss
AUDIOGRAM0-15 dB Normal.15-25 dB Minimal hearing loss.26-40 dB Mild hearing loss.41-55 dB Moderate hearing loss.56-70 dB Moderately severe hearing loss.71-90 dB Severe hearing loss.>90 dB Profound hearing loss.