Effects of temporal distortions on consonant perception with and without undistorted visual speech cues.

Effects of temporal distortions on consonant perception were measured using locally time-reversed nonsense syllables. Consonant recognition was measured in both audio and audio-visual modalities for assessing whether the addition of visual speech cues can recover consonant errors caused by time reversing. The degradation in consonant recognition depended highly on the manner of articulation, with sibilant fricatives, affricates, and nasals showing the least degradation. Because consonant errors induced by time reversing were primarily in voicing and place-of-articulation (mostly limited to stop-plosives and non-sibilant fricatives), undistorted visual speech cues could resolve only about half the errors (i.e., only place-of-articulation errors).