The influence of noise of different configurations on the hearing sensitivity to the dynamic changes in sound spectrum
The influence of noises of different configurations on sensitivity to dynamic changes in sound spectrum was investigated. The narrow band noise with ripple spectrum was used as a test signal. The central frequency of the test was 2 kHz and the intensity was 80 dB SPL. One octave band-pass noise was used as a masker. Three masker frequencies were tested: lower, on, and higher than the spectrum of the test signal. Intensity of masker varied from 60 to 100 dB SPL. The largest effect of the masker was observed at on-frequency masker: masking was observed when the masker/test ratio was -10 dB and higher. Shift of ripple spectrum cannot be detected by the listeners when the masker/test ratio was 10 dB or higher. A significant effect from low-frequency masker was observed when the masker level was 5 dB higher than the test; when masker/test ratio was 20 dB or higher, listeners could not detect the shift in the spectrum. The masker effect did not occur at the high-frequency masker up to masker/test ratio of 20 dB. A model that explains these dependences is suggested.