Patent ID: 8494844

Claim:
A method for selecting a segment of a sound sample of a subject's voice that has been digitized by an analog to digital converter, comprising the steps of: (a) receiving the sound sample comprising a time series of digital samples; (b) determining a plurality of segments, each segment comprising a pre-defined number of consecutive digital samples; (c) for each segment, calculating the value of a quality measure, the quality measure being a real-valued function of at least one parameter of the segment, the parameter reflecting the suitability of the segment for use in computing clinical metrics; (d) selecting the segment that has the greatest value of the quality measure, the quality measure being greater for segments that are more suitable for use in computing clinical metrics; and (e) storing the selected segment, or a pointer to the selected segment, in a memory; wherein the quality measure is the product of functions w 1 , w 2 , w 3 , w 4 , and w 5 , where: (a) w 1 is a monotonically increasing, non-negative real-valued function computed on input value r N , where r N is the ratio of the sound pressure level of the segment to the estimated background noise, measured in decibels; (b) w 2 is a monotonically decreasing, non-negative real-valued function computed on input value CV SPL , where CV SPL is the ratio of the standard deviation of the sound pressure level for the segment to the mean of the sound pressure level for the segment; (c) w 3 is a monotonically decreasing, non-negative real-valued function computed on input value r c , where r c is the fraction of digital samples in the segment that are clipped by the analog-to-digital converter; (d) w 4 is a monotonically increasing, non-negative real-valued function computed on input value r v where r v is the fraction of the segment that is voiced; and (e) w 5 is a monotonically decreasing, non-negative real-valued function computed on input value CV F0 , where CV F0 is the ratio of the standard deviation of the fundamental frequency for the segment to the mean of the fundamental frequency for the segment.