Through psychoacoustical experiments, H.Kato (ATR, 1998) revealed that the perceptual salience of the temporal cues embedded in speech sounds can be described more effectively in terms of a fundamental auditory base, i.e., loudness, than by linguistic terms such as syllables or morae[35]. Interestingly, the experiment was designed to address the perceived distortion degree by the compensatory modifications of C-V and V-C boundaries when one of the paired segments (consonant or vowel) was shortened or lengthened. But any neither C-V nor V-C was qualified by the results. Instead, the results imply that the salience of temporal cues depends upon a psychophysical auditory basis that tends to regard a large loudness jump as a significant marker. In his paper, it was also pointed out that the reason why either C-V or V-C supporters has partly succeeded in explaining the perceptual consequences of speech rhythms is that such boundaries incidentally coincide with majoy loudness jumps in speech. From a psychoacoustical viewpoint, his conclusion is not surprising at all because it simply suggests that a large and rapid change in the acoustic energy is perceptually salient.
