Spread of masking in normal subjects and in subjects with high-frequency hearing loss.

Upward spread of masking and remote masking were investigated in 4 subjects with closely matched high-frequency hearing losses. Masked thresholds in the presence of a high-frequency or a low-frequency bandpass noise were obtained using an adaptive-threshold procedure. 'Abnormal' upward spread of masking existed for the impaired subjects at some test frequencies when compared to the masking predicted on the basis of normal masking results and hearing-impaired quiet thresholds. Remote masking thresholds were usually shifted to the same absolute levels for normal and hearing-impaired subjects. These results demonstrate that speech reception in noise for listeners with high-frequency hearing loss could be affected by spread of masking and levels of hearing loss.