4aSC38. Characterizing human ability to discriminate talkers over low data rate voice coders.

Session: Thursday Morning, December 5


Author: Astrid Schmidt-Nielsen
Location: Naval Res. Lab., Washington, DC 20375-5337


Talker discrimination over low data rate voice coders (2400 bits/s) was evaluated in three separate experiments using a paired comparisons task. Test materials were Harvard sentences spoken by ten male and ten female talkers from the Boston area. Listeners were asked to decide whether two different sentences were spoken by the same person or by two different people. They then judged how dissimilar the two voices were using a five-point scale. The ability to discriminate among the voices (measured by d[sup ']) was compared to the subjective judgments of the perceptual distance between the voices. The effect of different types of voice coders on talker discriminability and on the perceived talker space was compared with uncoded speech. Comparisons with traditional measures of intelligibility and voice quality suggest that higher intelligibility or quality scores are not necessarily related to better talker discrimination, but dissimilarity ratings of different talkers were more closely related to voice quality scores. Listeners from two different parts of the country also perceived the talker space differently. [Work supported by NAVSPAWARSYSCOM.]

ASA 132nd meeting - Hawaii, December 1996