Although the inherent characteristics of poststimulatory auditory fatigue have been studied for some time, it has not been until the last decade that interest has been shown in a relatively new method of measuring auditory threshold changes due to sound stimuli. A number of specific clinical techniques have been reported for discerning temporary shifts in threshold that occur during periods of sustained-tone stimulation. The results of studies carried out with two of these techniques have led to a number of interesting practical speculations that have been applied to the clinical evaluation of abnormal hearing.
Dix, Hallpike, and Hood1-5 have stressed two major factors which discriminate post-stimulatory fatigue from abnormal loudness level losses that occur during periods of tone stimulation. The first of these is that the amount of fatigue following a tone stimulus is dependent on the physical magnitude of the stimulus. However, changes in loudness level that occur