Patent ID: 7565285
Filing Date: 2009-07-21
Classification: G10L

Abstract:
1. A method for using jitter variations in fundamental frequency of the voice of a person being evaluated for near-term suicidal risk, in determining such person to be at near-term risk for suicide based on measured difference between fundamental frequencies of two consecutive speech segments for such person as compared to speech fundamental frequency variations for persons known not to be at near-term suicidal risk comprising the steps of: A. setting an analysis window to a selected sample set length in excess of 3 where the particular sample is identified as the Kth sample; B. computing the wavelet transform for the sample set at scale 2 to the 4th power, with a scale factor defined by the quotient of the wavelet center frequency at level 0 and the desired center frequency; C. selecting two consecutive segments of the vocal signal of such person which are voiced segments and generating separate pulse trains in which the heights of the pulses correspond to amplitude of positive and negative peaks of the wavelet transformed speech signal; D. thresholding the segments of the vocal signal to discard peaks corresponding to possible unvoiced samples; E. computing a fundamental period over the entirety of each of the two segments by: F. determining period-to-period fluctuation of fundamental frequency by measuring the difference between fundamental frequencies of two consecutive segments; and G. comparing the measured difference between fundamental frequencies of two consecutive segments for such person to variations in fundamental frequency for persons known not to be at near-term suicidal risk and providing a signal to a clinician in the event such comparison finds the person to be at near-term risk for suicide.