On the relationship of stapedial contraction to central masking.
The auditory masked threshold of a 1-kc/s pure tone was determined in quiet and with levels of white noise at 50-80 db SL in the non-test ear. Two groups of normal-hearing adults were tested, one (N:14, mn age = 27.4 yrs) with no history of middle-ear pathology, and another (N:12, mn age = 44.7 yrs) with the stapedial tendon severed. Significant differences in the amount of masked-threshold shift were observed, greater shifts being seen for the normal Ss, additional shifts ranging from 0.8-4.3 db as masking increased from 50-80 db SL. These differences were judged to be at least partly the result of stapedial contraction rather than having their origin entirely in central masking as often assumed.
D000293:Adolescent; D000328:Adult; D000368:Aged; D001309:Auditory Threshold / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009119:Muscle Contraction; D009132:Muscles / Q000502:physiology*; D010470:Perceptual Masking; D012022:Reflex, Acoustic; D013198:Stapedius / Q000502:physiology*