Audiology tests your ability to hear sounds. Sounds vary according to the intensity (volume or loudness) and the tone (the speed of sound wave vibrations). Hearing occurs when sound waves are conducted to the nerves of the inner ear and from there to the brain. Sound waves can travel to the inner ear by air conduction (through the ear canal, eardrum, and bones of the inner ear) or bone conduction (through the bones around and behind the ear). The intensity of sound is measured in decibels (dB). A whisper is about 20 dB, loud music (some concerts) is around 80 to 120 dB, and a jet engine is about 140 to 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 to 60 Hz, while shrill, high - pitched tones range around 10,000 Hz or higher. The normal range of human hearing is about 16 Hz to 16,000 Hz. Some people can hear within a slightly higher range, and animals can hear up to about 50,000 Hz.

Alternative Names

Audiometry; Hearing test; Audiography; Audiogram