An audiology exam tests your ability to hear sounds. Sounds vary based on their loudness (intensity) and the speed of sound wave vibrations (tone).
Hearing occurs when sound waves are converted into electrical energy, which stimulates the nerves of the inner ear. Eventually the sound travels along nerve pathways to the brain.
Sound waves can travel to the inner ear through the ear canal, eardrum, and bones of the middle ear (air conduction), or through the bones around and behind the ear (bone conduction).
The INTENSITY of sound is measured in decibels (dB):
A whisper is about 20 dB
Loud music (some concerts) is around 80 - 120 dB
A jet engine is about 140 - 180 dB
Usually, sounds greater than 85 dB can cause hearing loss in a few hours. Louder sounds can cause immediate pain, and hearing loss can develop in a very short time.
The TONE of sound is measured in cycles per second (cps) or Hertz:
Low bass tones range around 50 - 60 Hz
Shrill, high-pitched tones range around 10,000 Hz or higher
The normal range of human hearing is about 20 Hz - 20,000 Hz. Some animals can hear up to 50,000 Hz. Human speech is usually 500 - 3,000 Hz.
The first steps are to see whether you need an audiogram. The specific procedures may vary, but they generally involve blocking one ear at a time and checking your ability to hear whispers, spoken words, or the sound of a ticking watch.
A tuning fork may be used. The tuning fork is tapped and held in the air on each side of the head to test the ability to hear by air conduction. It is tapped and placed against the mastoid bone behind each ear to test bone conduction.
Occupational hearing loss (1 image)(Doctor-Reviewed information)
Occupational hearing loss is damage to the inner ear from noise or vibrations due to certain types of jobs or entertainment.Occupational hearing loss is a form of acoustic trauma caused by exposure to vibration or sound. Sound is heard as the ear ...Reviewer: Alan Lipkin, MD, Otolaryngologist, Private Practice, Denver, Colorado. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.Date: 10/10/2008
Age-related hearing loss (1 image)(Doctor-Reviewed information)
Age-related hearing loss, or presbycusis, is the slow loss of hearing that occurs as people get older.Tiny hairs inside your ear help you hear. They pick up sound waves and change them into the nerve signals that the brain interprets as sound. Reviewer: Michael Langan, M.D. Department of Geriatrics, Massachusetts General Hospital, Boston, MA. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc. Date: 11/04/2008
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