Perceptual effects of plosive feature modification.

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.