The influence of time delay on forward masking when spatially separated sound image reproduced with headphone

With the virtual reproduction of headphone,the influence of delay time between masker and masked signal on forward masking when sound images are virtually spatial separated in azimuth is studied.The result shows that the thresholds tend to decrease dramatically with the increase in delay time.Furthermore,in case of spatial separation,there are difierences of masking thresholds with the maximmn about 15 dB.However,when the masker level is 70 dB.the difference of the thresholds increases a little as the delay time increases from 20 ms to 40 ms,which can be explained by the time integration effect and basilar membrane response.