Abstract
It has been reported that the maximum and minimum data of the narrow-band (one octave) acoustic waveforms played a pivotal role in the sound reproduction by using the sinusoidal interpolation between two successive extrema. Although two indices of phase and quantization errors of the extrema have closely related to the perception of sound localization, and the form of amplitude envelope, respectively, which has regarded as a principal carrier of speech waveforms, the interaction between the two has remained unclear as to which is a critical factor in the auditory cognitive system. We produced two types of synthesized sounds, manipulating either time or amplitude of the extrema under condition that two sum squared errors between an unmodified sound and the two syntheses were mutually close. Scheffe's pair test has reported that the quality of synthesized 3-s speech and music with phase error was significantly lower than that of the corresponding sounds with quantization error, suggesting the cognitive superiority of phase error to noise in amplitude envelope. Besides, synthesized sounds with estimated extrema by using a least-square fit maintained almost the same quality of unprocessed sounds, when phase error was within the margin of four to nine percent, supporting the notion of an index, sensitive to the sound quality.
