Loudness discomfort level and acoustic reflex threshold for speech stimuli.

Loudness discomfort level (LDL) and acoustic reflex threshold (ART) measurements were obtained from subjects with normal hearing using several speech stimuli, as well as broad-band and speech-spectrum noise. The purpose of the investigation was to determine the LDL for a variety of representative speech samples, and to determine the relationship between the LDL and ART for selected speech and noise stimuli. For all stimuli, LDL measurements were relatively constant, but ART measurements decreased significantly for wide-band noise stimuli as compared with the speech stimuli. Mean differences between the two measures were consistent, but individual subject data were characterized by wide variability precluding accurate prediction of the LDL from ART measurements.