FREQUENCY BAND COMPRESSION AND EXPANSION BY RESPECTIVE EXCLUSION AND REPETITION OF TIME SEGMENTS

摘要

The compression or expansion of a frequency band, for example, of speech, is accomplished by exclusion or repetition of time segments in a frequency band. Information losses resulting from exclusion of time segments, and stutter effects resulting from repetition, depend on the length of the time segments. Only small losses or stutter effects occur if the ratio of the mean phonoid duration divided by the segment duration is equal to or smaller than the compression or expansion factor N. To obtain a high compression factor N, the segment frequency must be as high as possible, with the doubled pitch frequency the theoretical limit.