Perceptual effects of plosive feature modification

Abstract

In the 1970-1980's, a number of papers explored the role of the transitional and burst features in consonant-vowel context. These papers left unresolved the relative importance of these two acoustic cues. This research takes advantage of refined signal processing methods, allowing for the visualization and modification of acoustic details. This experiment explores the impact of modifying the strength of the acoustic burst feature on the recognition scores P c (SNR) (function of the signal-to-noise ratio), for four plosive sounds /ta, ka, da, ga/. These results show high correlations between the relative burst intensity and the scores P c (SNR). Based on this correlation, one must conclude that these bursts are the primary acoustic cues used for the identification of these four consonants. This is in contrast to previous experiments, which used less precise methods to manipulate speech, and observe complex relationships between the scores, bursts and transition cues. In cases where the burst feature is removed entirely, it is shown that naturally existing conflicting acoustic features dominate the score. These observations seem directly inconsistent with transition cues playing a role: if the transition cues were important, they would dominate over low-level conflicting burst cues. These limited results arguably rule out the concept of redundant cues.

Within-consonant perceptual differences in the hearing impaired ear

“…This supports the hypothesis that the acoustic cues that are necessary for NH listeners are also necessary for the HI listeners, although they may not be sufficient. Thus, just as selective amplification of the NH cue region can manipulate the noise robustness of tokens for NH listeners (Kapoor and Allen, 2012), similar selective amplification might make a token more noise robust for HI listeners. For cases where the relative noise robustness of tokens for NH and HI listeners are inconsistent, other signal properties besides the intensity of acoustic cues (e.g.…”

“…The NH SNR 90 has been found to significantly correlate with the intensity of the time-frequency region that contains the primary consonant cues (R egnier and Allen, 2008;Li et al, 2010;Li et al, 2012;Kapoor and Allen, 2012). Thus the NH DSNR 90 relates the difference in intensity of the NH consonant cue regions.…”

“…Yet there are individual HI ears for which a DP e > 50% is observed for /z, p, s/. In such cases, additional signal properties, perhaps the presence of conflicting cues (Li et al, 2010;Li et al, 2012;Kapoor and Allen, 2012) or variations of the primary cues to which the HI ears could be sensitive, may play Fig. 1).…”

“…Previous studies have shown that for individual consonant tokens, the intensity of each necessary cue region is correlated to the robustness to noise for NH listeners (R egnier and Allen, 2008;Li et al, 2010;Li et al, 2012;Kapoor and Allen, 2012). We test if natural variations in the intensity of the acoustic cue region that affect NH perception at low SNRs would similarly affect HI perception at higher SNRs.…”

Speech Perception

“…/d/ in both cases, but the speech signal differs significantly in the two cases. Of course, not every scientist was convinced that phonemes did not have invariant signal properties in different vowel contexts, and research in the six or so decades since the original claim has continued to attempt to uncover these properties (e.g., Kapoor and Allen, 2012). Even so, no one has yet provided convincing evidence of invariance.…”