Talker effects in speech band importance functions

Abstract

The literature is somewhat mixed with regard to the influence of (a) the particular speech material (e.g., sentences or words) versus (b) the particular talker used to create the recordings, on band-importance function (BIF) shape. One possibility is that previous techniques for creating BIFs are not sensitive enough to reveal these influences. In the current investigation, the role of talkers was examined using the compound technique for creating BIFs. This technique was developed to account for the multitude of synergistic and redundant interactions that take place among various speech frequencies. The resulting functions display a complex microstructure, in which the importance of adjacent bands can differ substantially. It was found that the microstructure could be traced to acoustic aspects of the particular talkers employed. Further, BIFs for IEEE sentences based on ten-talker recordings displayed less microstructure and were therefore smoother than BIFs based on one such talker. These results together suggest that the compound technique is sensitive enough to reveal acoustic aspects of the particular talker employed. It is further suggested that multiple talkers, rather than smoothing of the functions, be used if the goal is to describe speech more generally.