1. Chapter 10 Hearing and Deafness
Chapter 10 slides in Children with Disabilities, Seventh Edition, Online Companion Materials.
Copyright © 2013 Paul H. Brookes Publishing Co., Inc. All rights reserved.

2. The Hearing System
The anatomical mechanism for hearing is divided into a peripheral auditory mechanism and a central auditory system
Peripheral auditory system divided into external, middle, and inner ear
External ear includes auricle and ear canal
Eardrum (tympanic membrane) separates external ear from middle ear
Inner ear composed of the vestibular system (contains sensory organ of balance) and the cochlea (houses sensory organ of hearing)
Chapter 10 slides in Children with Disabilities, Seventh Edition, Online Companion Materials.
Copyright © 2013 Paul H. Brookes Publishing Co., Inc. All rights reserved.

3. Defining Sound
When we hear a sound, we are actually processing and interpreting a pattern of vibrating air molecules
Movement of molecules is described in terms of the frequency of oscillations and the amplitude of the oscillations from the resting point
Frequency of sound perceived as pitch and measured in cycles per second, or hertz (Hz)
The more cycles that occur per second, the higher the frequency, or pitch, of the sound
Chapter 10 slides in Children with Disabilities, Seventh Edition, Online Companion Materials.
Copyright © 2013 Paul H. Brookes Publishing Co., Inc. All rights reserved.

4. Defining Hearing Loss Categories of degree of hearing loss:
Minimal, mild, moderate, severe, and profound
Each child’s hearing capacity varies as a consequence of listening circumstances
Types of hearing loss:
Temporary conductive hearing loss (CHL)
Permanent hearing loss: four types include sensorineural, permanent conductive, mixed loss, and neural hearing disorders
Chapter 10 slides in Children with Disabilities, Seventh Edition, Online Companion Materials.
Copyright © 2013 Paul H. Brookes Publishing Co., Inc. All rights reserved.

5. Defining Hearing Loss (continued)
Degrees of hearing loss
Defining degree of hearing loss helps predict difficulty a child will have in acquiring language and information through hearing
Categorized from minimal to profound using a classification scale
Effects of hearing loss on functional communication vary according to severity
Mild loss—difficulty hearing distant or soft sounds
Moderate loss—may hear conversational speech as whisper
Profound loss—may hear very loud environmental sounds but not conversational speech
Chapter 10 slides in Children with Disabilities, Seventh Edition, Online Companion Materials.
Copyright © 2013 Paul H. Brookes Publishing Co., Inc. All rights reserved.

6. Causes of Hearing Loss Genetic causes
For approximately 80% of children with hereditary hearing loss, the loss is inherited as an autosomal recessive trait
More than 200 documented inherited syndromes are associated with deafness
Pre-, peri-, and postnatal factors that can result in sensorineural hearing loss (SNHL)
Environmental exposures to viruses, bacteria, and other toxins prior to or following birth
Severe respiratory or cardiopulmonary disease in neonate
Very low birth weight
Infections
Infections during pregnancy, infancy, and childhood can cause SNHL
Chapter 10 slides in Children with Disabilities, Seventh Edition, Online Companion Materials.
Copyright © 2013 Paul H. Brookes Publishing Co., Inc. All rights reserved.

7. Causes of Hearing Loss (continued)
Ototoxic medications
Specific antibiotics used to treat severe bacterial infections and chemotherapy drugs used to treat cancer can cause bilateral SNHL
Middle ear disease
Otitis media with effusion (OME): middle ear infection with fluid accumulation
Treated by antibiotics and pressure equalization (PE) tubes; minimal to mild CHL
Trauma
Skull base fractures may cause a sudden or bilateral SNHL or permanent CHL
Chapter 10 slides in Children with Disabilities, Seventh Edition, Online Companion Materials.
Copyright © 2013 Paul H. Brookes Publishing Co., Inc. All rights reserved.

8. Causes of Hearing Loss (continued)
Noise exposure: sudden, explosively loud noises (firecrackers or fireworks) or repeated exposure to very loud sounds over time (iPod at high-intensity levels or attending live rock music concerts)
Syndromes associated with intellectual disability
Children with intellectual disabilities are at increased risk for hearing loss, especially when genetic condition is cause of disability (i.e., Down syndrome)
Aggressive medical and surgical interventions for persistent middle ear effusions decrease incidence rates of CHL
Chapter 10 slides in Children with Disabilities, Seventh Edition, Online Companion Materials.
Copyright © 2013 Paul H. Brookes Publishing Co., Inc. All rights reserved.

9. Identification of Hearing Loss
Early identification accomplished through universal newborn hearing screenings at birthing hospitals
Rates of hearing loss and associated risk factors
Only 50% of infants with SNHL at birth have identifiable risk-history factors
Factors indicating possible hearing loss
Parental concern
Hearing milestones for detecting hearing loss
Signs of hearing loss in deaf or hard-of-hearing child
Baby does not awaken to loud noises, babbling does not become meaningful, and receptive language lags
Chapter 10 slides in Children with Disabilities, Seventh Edition, Online Companion Materials.
Copyright © 2013 Paul H. Brookes Publishing Co., Inc. All rights reserved.

10. Identification of Hearing Loss (continued)
Methods of screening for hearing loss
Otoacoustic emissions (OAE) technology and automated auditory brainstem response (ABR)
Newborn screening for hearing loss
Well-baby nursery: screened before hospital discharge
Neonatal intensive care unit (NICU): recommended that NICU infants be screened with automated ABR
Hearing tests
Electrophysiological methods
Behavioral hearing tests
Chapter 10 slides in Children with Disabilities, Seventh Edition, Online Companion Materials.
Copyright © 2013 Paul H. Brookes Publishing Co., Inc. All rights reserved.

11. Intervention for Hearing Loss
Early intervention
Methods of intervention
Language-learning options (such as cued speech and American Sign Language)
Amplification (hearing aids, assistive listening devices)
Cochlear implantation for severe or profound sensorineural hearing loss
Education and communication
Outcome: focus on early identification of hearing loss and prompt intervention that is individually tailored, family- centered, and carefully monitored
Chapter 10 slides in Children with Disabilities, Seventh Edition, Online Companion Materials.
Copyright © 2013 Paul H. Brookes Publishing Co., Inc. All rights reserved.