A MEASURE OF APERIODICITY AND PERIODICITY IN SPEECH

In this paper, we discuss a direct measure for aperiodic energy and periodic energy in speech signals. Most measures for aperiodicity have been indirect, such as zero crossing rate, highfrequency energy and the ratio of high-frequency energy to lowfrequency energy. Such indirect measurements will usually fail in situations where there is both strong periodic and aperiodic energy in the speech signal, as in the case of some voiced fricatives or when there is a need to distinguish between high frequency periodic versus high frequency aperiodic energy. We propose an AMDF based temporal method to estimate directly the amount of periodic and aperiodic energy in the speech signal. The algorithm also gives an estimate of the pitch period in periodic regions. 1