A pitch-synchronous analysis of hoarseness in running speech.
A method of pitch-synchronous acoustic analysis of hoarseness requiring a voice sample of only four fundamental periods is presented. This method calculates a noise-to-signal (N/S) ratio, which indicates the depth of valleys between harmonic peaks in the power spectrum. The spectrum is calculated pitch synchronously from a Fourier transform of the signal, windowed through a continuously variable Hanning window spanning exactly four fundamental periods. A two-stage procedure is used to determine the exact duration of the four fundamental periods. An initial estimate is obtained using autocorrelation in the time domain. A more precise estimate is obtained in the frequency domain by minimizing the errors between the preliminary calculated power spectrum and the predicted spectrum spread of a windowed harmonic signal. Analysis of synthesized voices showed that the N/S ratio is sensitive to additive noise, jitter, and shimmer, and is insensitive to slow (8 Hz) modulation in fundamental frequency and amplitude. An analysis of pre- and postoperative voices of six patients with benign laryngeal disease showed that the N/S ratio for vowel /u/ in running speech consistently improved after surgery for all subjects, in agreement with their successful therapeutic results.
Muta
H
H
Haskins Laboratories, New Haven, Connecticut 06511.
Baer
T
T
Wagatsuma
K
K
Muraoka
T
T
Fukuda
H
H
D006685:Hoarseness / Q000503:physiopathology*; D006801:Humans; D007830:Larynx / Q000503:physiopathology; D013018:Sound Spectrography; D014833:Voice Quality