Speech recognition and just-follow-conversation tasks for normal-hearing and hearing-impaired listeners with different maskers.

Speech recognition (SRT) and just-follow-conversation (JFC) tasks were performed by normal-hearing and hearing-impaired listeners matched for age and sex using three masking backgrounds: speech spectrum random noise, continuous forward speech and reversed speech. In the SRT task, the signal-to-noise (S/N) ratio for 50% correctly repeated words of short, 5-word, low-redundancy sentences was determined. In the JFC task, the listener adjusted the speech level until he felt he could just understand what was being said. The listeners needed a higher S/N ratio for the JFC task than for the SRT task. The speech maskers gave less masking than the random noise. No difference between forward and reversed speech was observed. The hearing-impaired listeners needed a higher S/N ratio than the normal-hearing subjects. Correlations between results obtained with the SRT and the JFC techniques were significant with speech but not with random noise as masker. The highest correlations between pure-tone hearing thresholds at different frequencies and results in the SRT and JFC tests were seen at 0.5 and 1 kHz.