Luscher's test (E. Luscher) is a method for studying the function of hearing by the magnitude of the differential (difference) threshold of sound power perception with the help of modulations. The differential perception threshold of sound intensity is understood to mean the minimum fluctuation of sound intensity, which causes the sensation of a change in its volume. The normal value of the differential threshold for a tone of 1000 Hz with an intensity of 40 dB above the threshold is 0.9-1.5 dB. The decrease in this value indicates the presence of the phenomenon of accelerating the increase in loudness, which is observed in violation of the function of the hair cells of the organ of Corti, but is absent in the case of retrocochlear lesions and disturbances in sound conduction.
This makes Luscher's test, along with other methods for determining the phenomenon of the acceleration of loudness, an important method for the differential diagnosis of auditory disorders. Luscher's test can be used both for unilateral and bilateral hearing loss (see).