Audiometry and Hearing Disorders SPA 4302 Summer A

Audiometry and Hearing Disorders SPA 4302 Summer A 2004

The Evolution of Audiology • “Audiology”=audire (Latin=to hear) + logos (Greek=the study of) • Post-World War II—military aural rehabilitation centers for veterans. • Scope of practice grew with changing technology • Educational requirements moved from – Bachelor’s degree – Master’s degree (1960’s) – Doctor of Audiology (1990’s) • Audiologist—an individual who “is uniquely qualified to provide a comprehensive array of professional services related to the assessment and habilitation/rehabilitation of persons with auditory and vestibular impairments, and to the prevention of these impairments” (American Academy of Audiology, 1997)

Prevalence/Impact of Hearing Loss • • • 26 million people have hearing impairment 30 million are regularly exposed to hazardous noise levels 10 million have permanent noise-induced hearing loss 6 out of 1000 children are born with a hearing impairment By age 6, 90% of US children have had at least one ear infection Frequent ear infections can significantly impair speech and language development and academic performance • For older adults, hearing loss can impact personal relationships and is related to overall poor health, decreased physical activity, and depression • Northern and Downs (2002)—for a 1 year-old child with severe hearing impairment and average life expectancy of 75 years, the economic burden can approach $2 million

Audiology Specialties • • • Medical Audiology Educational Audiology Pediatric Audiology Dispensing/Rehabilitative Audiology Industrial Audiology

Where do we work? • Almost 80% of audiologists ID themselves as direct clinical service providers • Most audiologists work within a medical environment (physician’s office, hospitals, etc. ) • The most rapidly growing setting is private practice (largely due to the development of the Au. D. ) • Other settings: – Schools, College/University, Speech & Hearing Center, Residential Home Health Care, Industrial

Professional Societies • American Speech-Language-Hearing Association (ASHA)—first professional society for audiologists (1947) • American Academy of Audiology (AAA)—founded in 1988 • Academy of Rehabilitative Audiology • Academy of Dispensing Audiologists • Educational Audiology Association • American Auditory Society • Self Help for Hard of Hearing People, Inc. • Alexander Graham Bell Association for the Deaf

Anatomy and Physiology of the Ear

Inner Ear

Pathways of Sound • Air Conduction—sound travels through the outer ear, middle ear, inner ear, and neural pathways • Bone Conduction—sound bypasses the outer ear and middle ear by vibrating the skull mechanically and stimulating the inner ear directly

AIR CONDUCTION

Bone Conduction

Types of Hearing Loss • Conductive Hearing Loss – Hearing by air conduction will be impaired, but hearing by bone conduction will be normal • Sensorineural Hearing Loss – Hearing by air conduction and bone conduction will be impaired • Mixed Hearing Loss – Hearing by air conduction and bone conduction will be impaired, but hearing loss will be greater by air conduction

Hearing Tests • Early tests that provided little information: – Clapping the hands – Making various vocal sounds – Ticking of a watch – Clicking 2 coins together

Tuning Fork Tests • First used in the 19 th Century • Tuning forks emit a pure tone at a specific frequency Schwabach Test—hearing sensitivity of a patient vs. that of the tester Rinne Test—patient’s hearing sensitivity by bone conduction vs. by air conduction Bing Test—hearing by bone conduction with/out occlusion Weber Test—lateralization of bone conducted tone: unilateral sensorineural hearing loss-- heard in better ear; unilateral conductive hearing loss – heard in poorer ear