Tolerable Limit of Loudness: Its Clinical and Physiological Significance

TLDR: In this article, a large group of subjects with unilateral end-organ deafness, in all of whom the presence of loudness recruitment had been verified by means of the alternate binaural loudness balancing procedure.

Abstract: In the normal‐hearing subject, a sensation of unpleasant loudness is invariably associated with intensities of the order of 100 dB within the frequency range 500–4000 cps. This is referred to as the loudness‐discomfort level (LDL). The intensity distribution of LDL has been established in a large group of subjects with unilateral end‐organ deafness, in all of whom the presence of loudness recruitment had been verified by means of the alternate binaural loudness balancing procedure. In these, the distribution was similar to that of a normal‐hearing group. By contrast, the LDL's of subjects with conductive or nerve‐fibre deafness exceeded the maximum available audiometer intensity of 120 db. The test, therefore, is of particular value in establishing the presence or absence of loudness recruitment in bilateral deafness. These findings suggest a physiological limit of loudness perception, the theoretical implications of which are discussed.