1. Audiometry and Hearing Disorders
SPA 4302
Summer A 2004

2. 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)

3. 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

4. Audiology Specialties
Medical Audiology
Educational Audiology
Pediatric Audiology
Dispensing/Rehabilitative Audiology
Industrial Audiology

5. 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

6. 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

7. Anatomy and Physiology of the Ear

8. Inner Ear
Middle Ear
Outer Ear

9. 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

10. AIR
CONDUCTION

11. Bone
Conduction

12. Types of Hearing Loss (Both) 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
(Outer/Middle Ear)
(Inner Ear/Neural)
(Both)

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

14. Tuning Fork Tests First used in the 19th 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