Effect of peripheral hearing loss on the masking level difference.

The effects of both symmetric and asymmetric peripheral hearing loss on the masking level difference (MLD) at 500 Hz were studied in 651 subjects with conductive or sensorineural hearing loss and 270 normal controls. The data supported the hypothesis that the modification in MLD due to peripheral hearing loss results from deterioration in threshold in the antiphasic condition. These results provide correction factors for the normal MLD range as functions of boundary frequency of sensorineural loss above 500 Hz and degree of both symmetric and asymmetric sensitivity loss at 500 Hz in both subjects with conductive hearing loss and those with sensorineural hearing loss.