Screening audiometers: What do they do?
Screening audiometers produce a restricted range of pure tones of varying frequency and intensity. Frequency is measure in Hertz (Hz) and is perceived as pitch. Intensity is measured in decibels (dB) and is perceived as loudness. Screening audiometers typically provide for a sweep across the frequencies important for speech (500 Hz to 4000 Hz) at a fixed intensity, usually 25 dB HL. Typically, the patient who hears all the tones has normal hearing, and a miss constitutes a fail. In other words, its a yes/no type of test. For testing patients over age 65, a screener that can also test at the 40 dB HL level is advised. Another alternative is the use of a full threshold test. A threshold is the faintest sound that the average listener can just hear in a quiet environment. A threshold test is used to obtain more information about hearing at each of about four to eight frequencies.
