Short-term and long-term effects on the masking level difference following middle ear surgery.
The masking-level difference (MLD) was measured in a group of adult listeners having unilateral otosclerosis before stapedectomy surgery, 1 month following surgery, and 1 year following surgery. The results indicated that the MLD in this group improved significantly over each of the sequential tests. In contrast, for a group of normal-hearing listeners, the MLD did not change significantly over sequential testing. The results support an interpretation that a period of exposure to abnormal binaural auditory input (as occurs in a unilateral conductive loss) can blunt sensitivity to binaural cues after normal binaural input has been restored in most adult listeners, however, there appears to be a relatively long-term readjustment or adaptation, such that the sensitivity to binaural cues recovers to a normal or near-normal level at the 1-year postsurgery retest. Two of eight listeners did not show recovery to a normal MLD value over this time period. The efficiency and rate of readjustment may differ among individuals.
Hall
J W
JW
Division of Otolaryngology/Head & Neck Surgery, University of North Carolina Medical School, Chapel Hill 27599.
Grose
J H
JH
D000161:Acoustic Stimulation; D000328:Adult; D001309:Auditory Threshold; D004432:Ear, Middle / Q000503:physiopathology / Q000601:surgery*; D005260:Female; D006309:Hearing; D006314:Hearing Loss, Conductive / Q000175:diagnosis / Q000209:etiology / Q000503:physiopathology; D006320:Hearing Tests; D006801:Humans; D008297:Male; D008875:Middle Aged; D010040:Otosclerosis / Q000150:complications / Q000503:physiopathology / Q000601:surgery*; D010470:Perceptual Masking; D013201:Stapes Surgery / Q000379:methods*