Rate-dependent perception of aspiration and pre-aspiration in Icelandic.

Speech segments are highly context-dependent and acoustically variable. One factor that contributes heavily to the variability of speech is speaking rate. Some speech cues are temporal in nature-that is, the distinctions that they signify are defined over time. How can temporal speech cues keep their distinctiveness in the face of extrinsic transformations, such as those wrought by different speaking rates? This issue is explored with respect to the perception, in Icelandic, of Voice Onset Time as a cue for word-initial stop voicing, word-initial aspiration as a cue for [h], and Voice Offset Time as a cue for pre-aspiration. All the speech cues show rate-dependent perception though to different degrees, with Voice Offset Time being most sensitive to rate changes and Voice Onset Time least sensitive. The differences in the behaviour of these speech cues are related to their different positions in the syllable.