An Experimental Study of Speech-Wave Probability Distributions

Measurements were made of the first-probability distribution and of various conditional probability distributions of the speech wave instantaneous amplitude. Results obtained for several speakers indicate that the first-probability distribution varies exponentially with large values of amplitude and that increases in the conditional probabilities are noted for delay times of the order of magnitude of the pitch period. Measurements were also made of the first-probability distribution of the duration of the speech-wave zero-crossing periods, and of the auto-correlation function of clipped speech. These measurements were of the stationary, or “long-time,” speech-wave probability distributions. Most of the results are for speech waves recorded in an anechoic chamber. Some results are included for voices recorded in a live studio.