Speech recognition in noise, temporal and spectral resolution in normal and impaired hearing

A battery of tests for the evaluation of temporal (forward masking) and spectral (detection of frequency change; critical band for masking; psychoacoustic tuning curve) resolution in hearing with regard to the importance for speech recognition in noise has been applied to two groups of subjects. One group of 10 listeners had normal hearing, while the other consisted of 11 subjects with moderate, sloping sensorineural hearing loss. Significant differences were found between the two groups in all parameters except critical bandwidth for masking. Correlation analysis on the test results from the combined groups of subjects showed that speech recognition in noise was best correlated with the average hearing threshold levels at 2 and 4 kHz, followed by forward masking and psychoacoustic tuning curves at 4 kHz. The correlation coefficients were approximately 0.7, 0.6 and 0.55, respectively. Detection of frequency change and critical bandwidth show the lowest correlations to speech recognition in noise.