Relationship between loudness discomfort level and acoustic reflex threshold for normal and sensorineural hearing-impaired individuals.

The relationship between loudness discomfort level (LDL) and acoustic reflex threshold (ART) was determined by comparing the ART to the LDL obtained by the psychophysical method of constant stimuli. Randomly presented stimuli of 1000 Hz, 2000 Hz, and a multi-talker speech noise were presented to normal and sensorineural hearing-impaired listeners. The listener's task was to judge whether the stimulus was at a level that was: (1) too loud or uncomfortably loud; or (2) not too loud or not uncomfortably loud. Prior to the judgement of the subject acoustic reflex threshold were determined. Both LDL and ART were found to be significantly higher for the hearing-impaired group. For the pure tone stimuli, LDL for the hearing-impaired group was at or below the ART. Significant differences were shown to exist between LDL and ART for each group. A multiple regression analysis indicated significant correlations between LDL and ART. Ranges of prediction error were selected to investigate the ability of ART to predict LDL. Both pure tone and speech ART successfully predicted LDL within +/- 10 dB for a high percentage of the subjects.