On time-frequency masking in voiced speech

This paper addresses the issue of masking of noise in voiced speech. First, we examine the audibility of cyclostationary narrow-band noise bursts added to voiced speech generated by synthetic excitation. Varying the temporal location of noise within a pitch cycle corresponds to varying its phase spectrum. Using this fact, we found that a change of phase of the noise in the high frequency region is more perceptible for a low-pitched sound than for a high-pitched sound. We then propose a pitch-dependent temporal weighting function which can be employed in quantization of pitch cycle waveforms. In a second experiment, we found that the audibility of high-frequency noise added to natural speech can be significantly reduced using this weighting function