Communication Sciences and Disorders Test 6 Tiffany Carpenter Chapter 14 Audiology and Hearing Loss Prevalence and Incidence of Deafness and Hearing Impairment General estimate 10 of the US Population about 31 5 million Hearing loss 3 in 1 000 births Deafness 1 in 1 000 births Educationally significant hearing loss 83 in 1 000 children Deaf Culture A view of life manifested by the mores beliefs artistic expression understanding and language ASL that is particular to Deaf people Schools for the deaf provide a means for children to interact freely using ASL What Is Audiology Discipline involved in o Prevention and assessment of auditory vestibular and related impairments as well as habilitation rehabilitation and maintenance Audiologists therapies o Provide counseling providing and fitting amplification various o Amplification technology such as hearing aids cochlear implants and assistive listening devices that improve access to sounds by electronically increasing their intensity Audibility the ability to detect the presence of a given sound Intelligibility the ability to recognize and understand what is heard Hearing loss affects both audibility and intelligibility Measuring Hearing frequency vs intensity First the vibrating object travels a measureable distance in either direction This is referred to as the amplitude of the vibration The amplitude determines Intensity measure of the magnitude of sound o Measured in decibels dB o Think intensity dB Secondly this back and forth movement regularly repeats itself resulting in a certain number of complete cycles during a specified period of time This is referred to as the Frequency number of wave cycles that are completed within a specific time period pitch of the sound o Measured in cycles per second or Hertz Hz o Think frequency of cycles Basic Anatomy of the Ear The Outer Ear Pinna enhances sound aids localization External auditory meatus elliptical tube lined with skin Extends from concha to the eardrum Glands that produce cerumen The Middle Ear Tympanic membrane eardrum o vibrates in response to sound Middle ear space tympanic cavity o located behind the tympanic membrane Air filled lined with mucous membrane Eustachian tube Ossicular chain o connects the middle ear with the nasopharynx located behind the nose and above the roof of the mouth o Spans the length of the middle ear cavity o Chain formed by 3 small bones Malleus incus and stapes The Inner Ear Two Major Components cochlea and vestibular Cochlea o Responsible for providing auditory input to the central auditory system o Hair cells Vestibular system o Supplies information for balance and spatial orientation o Related to vertigo the sensation of spinning dizziness and imbalance o Semicircular canals sense angular acceleration such as up and down and side to side head movement o Otolith system two membranous sacs that sense liner acceleration riding in an elevator or car Vestibulocochlear Nerve Eighth Cranial Nerve made up of neural fibers that originate in the vestibular and cochlear portions of the inner ear Traverses through the internal auditory meatus bony canal Region marks the juncture of the peripheral and central auditory system Types of Hearing Loss Conductive hearing loss occurs as a result of a deformation malfunction or of the outer or middle ear Impacts audibility cases not usually obstruction permanent Disorders of the Outer Ear o Microtia refers to a small malformed pinna o Atresia complete closure of the external auditory meatus o Stenosis o Impacted cerumen or foreign object o Frequently occur with craniofacial disorders Disorders of the Middle Ear o Cholesteatoma o Otosclerosis ossicles Tumorlike mass composed of skin cells keratin and fat that migrates into the middle ear cavity often through a perforated eardrum Can grow in size and can erode bone including the Afflicts primarily young adults particularly females and is linked to genetic factors Resorption of healthy bone and subsequent formation of spongy bone in the vicinity of the stapes footplate This hardens results in partial complete fixation of the stapes o Otitis media Middle ear infection o Treatment Myringotomy An simple surgical procedure whereby an incision is made in the tympanic membrane and fluid within the middle ear cavity is drained Frequently followed by insertion of a pressure qualization tympanostomy tube serve same purpose of Eustachian tube Sensorineural Hearing Loss results from the absence or malformation of or damage to the structures of the inner ear most notably the hair cells within the cochlea May be present at birth or develop over one s life Usually permanent Aplasia Dysplasia embryonic development Due to the absence or malformation of the inner ear structures during the o Usher s syndrome severe to profound sensorineural hearing loss and visual impairment that results in night blindness and reduced peripheral vision o Waardenburg s syndrome mild to severe sensorineural hearing loss pigmentary discoloration of the irises and hair and craniofacial malformation of the nasal area o Alport s syndrome sensorineural hearing loss and kidney disease Maternal Rubella HIV STD bacterial or viral infections Contracted during the mother s pregnancy Meningitis Bacterial infection Mixed Hearing Loss the presence of both conductive and sensorineural hearing loss Central Auditory Processing Disorders Difficulty using and interpreting auditory information Genetics complications from otitis media or neurological May impact language learning and development Easily distracted difficulty understanding rapid speech and speech in poor Implications for social workplace communication in adults acoustic environments with reverberation Must administer a comprehensive battery Difficult to distinguish from other impairments Degrees of Hearing Loss Degree of hearing loss expressed in dB Normal range different for children and adults Slight mild to moderate severe is considered hard of hearing Severe to profound is considered deaf Levels of loss o 26 40 dB Mild Loss o 41 55 dB Moderate Los o 56 70 dB Moderately Severe Loss o 71 90 dB Severe Los o 91 dB Profound Loss Audiological Assessment Procedures Screening which individuals are likely to have a hearing loss Assessment when a screening is failed Assessing Infants and Children vs Adults o Commercially available instruments can be used with children o Adults with various disorders may require modifications o Nonorganic hearing loss Portray having