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.

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) https://www.youtube.com/watch?v=qgdqp-oPb1Q Chapter 10 slides in Children with Disabilities, Seventh Edition, Online Companion Materials. Copyright © 2013 Paul H. Brookes Publishing Co., Inc. All rights reserved.

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.

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.

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.

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.

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.

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.

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.

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.

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 https://www.youtube.com/watch?v=bUFibBxAkGQ https://www.youtube.com/watch?v=0CF0M1-jEFU Chapter 10 slides in Children with Disabilities, Seventh Edition, Online Companion Materials. Copyright © 2013 Paul H. Brookes Publishing Co., Inc. All rights reserved.