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Hearing. Chapter 12 Nannette Mentzer. Hearing. Defining Sound The Hearing System Hearing Loss Identification of Hearing Loss Hearing Screening and Testing Degrees of Hearing Loss Treatment of Middle Ear Disease Treatment of Hearing Loss Early Intervention Amplification
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Hearing Chapter 12 Nannette Mentzer
Hearing • Defining Sound • The Hearing System • Hearing Loss • Identification of Hearing Loss • Hearing Screening and Testing • Degrees of Hearing Loss • Treatment of Middle Ear Disease • Treatment of Hearing Loss • Early Intervention • Amplification • Communication and Education
When we hear sound we are interpreting a pattern of vibrating air molecules referred to as frequency. This frequency of sound is perceived as pitch and is measured in cycles per second or Hertz. The more cycles the higher the frequency.
The Hearing System The ear is divided into a peripheral auditory mechanism, which starts at the outer ear and ends at the auditory nerve. The central auditory system extends the auditory nerve to the brain. The defect in the peripheral system would indicate a hearing loss.
The peripheral auditory system External l Auricle and the ear canal Middle Ear Ear canal, eardrum (tympanic membrane), stapes, malleus, and incus (the ossicles), Eustachian tube, the oval window, Inner Ear The vestibular system and the cochlea
Hearing Loss Conductive Dysfunction of the middle or external ear Sensorineural dysfunction of the auditory nerve or the cochlea Mixed hearing loss there are conductive and sensorineural components to the hearing loss
Causes • Injury in utero, perinatal or after birth • prenatal and postnatal infections • anoxia • prematurity • exposure to ototoxic agents (antibiotics) • ear infections (conductive HL)
Genetic disorders associated with hearing loss Treacher Collins Syndrome Waardenburg Syndrome Laurence-Moon-Beidi Syndrome Usher Syndrome CHARGE Syndrome Down Syndrome Trisomy 13, Trisomy 18 Cleft Palate
Indications of Hearing Loss Not making reduplicated sounds Not babbling A baby does not awaken by loud noises Not following a verbal direction Not localizing
Which infants get screened for a hearing loss? According to the Joint Committee on Infant Hearing the “risk” factors are: family history infections such as rubella and syphilis bacterial meningitis congenital malformations of the head and neck prematurity anoxia hyperbilirubinemia requiring exchange transfusions
Hearing Tests Formal hearing tests tell whether there is a hearing loss, differentiate between conductive and sensorineural losses, determine the degree of the loss, estimate how speech speech sounds can be discriminated
Early Intervention Children need to be linked up with an interdisciplinary, comprehensive early intervention program.
Amplification Children should be aided with a hearing aid that works best for them. Assistive listening devices should be explored as well as the hearing aid when the child is included in the classroom.
Surgery Cochlear implants should be considered for children that do not benefit from amplification.