Simulation of the effects of high-frequency hearing impairment in noise and estimation of the effects of hearing aids incorporating filtering of low-frequency components in the presence of background noise.

An attempt was made to simulate the effects of high‐frequency hearing impairment in “noisy” situations. It was assumed that the difficulties experienced by individuals with high‐frequency hearing impairment in noise can be simulated, if in addition to the spectrum shaping of speech, the noise was also filtered. Such filtered noise, containing mainly low‐frequency elements was expected to effectively mask the only low‐frequency cues available after filtering the high‐frequency elements from the speech spectrum. The speech discrimination ability of normal individuals was also assessed in a condition where both the speech and noise were low pass filtered at 500 Hz. This condition was presented to simulate the effects of hearing aids incorporating noise‐suppressor switches that filter out both the noise and the low‐frequency speed cues in the presence of background noise. Detailed analyses of the results will be discussed.