Listener consistency in identifying speech mixed with particular “bubble” noise instances
Michael Mandel, Sarah E. Yoho, Eric W. Healy · The Journal of the Acoustical Society of America · 2015
Previous work has shown that the intelligibility of mixtures of the same exact speech token with different instances of “bubble” noise is highly dependent on the configuration of the random time-frequency glimpses it provides. In the current study, the consistency of these judgments was measured for such mixtures involving six consonants, /t/, /d/, /f/, /v/, /t͡ʃ/, /d͡ʒ/, in an /a/-consonant-/a/ context. Intra-subject consistency on ten repetitions each of 60 mixtures was found to be high, as was inter-subject consistency between five normal-hearing subjects on 1200 mixtures. In addition, the noise level at a small subset of time-frequency points was significantly correlated with the overall intelligibility of the mixtures of a given token, suggesting that these regions contribute more strongly to correct identification than others. The current study finds that these regions are quite consistent across the five subjects. For example, for the token /ada/, these points surround the stop burst and the resolved harmonics following the onset of voicing. These results show the promise of the “bubbles” methodology for identifying time-frequency regions of individual utterances that contribute most to their intelligibility, permitting future study of such regions for different types of speech and listeners. [Work supported by NIH.]