Acoustical properties of speech as indicators of depression and suicidal risk

Acoustic properties of speech have previously been identified as possible c ues to depression, and there is evidence that certain vocal parameters may be used further to objectively discriminate between depressed and suicidal speech. Studies were performed to analyze and compare the speech acoustics of separate male and female samples comprised of normal individuals and ind ividuals carrying diagnoses of depression and high-risk, near-term suicidal ity. The female sample consisted of ten control subjects, 17 dysthymic pati ents, and 21 major depressed patients. The male sample contained 24 control subjects, 21 major depressed patients, and 22 high-risk suicidal patients. Acoustic analyses of voice fundamental frequency (F-0), amplitude modulati on (AM), formants, and power distribution were performed on speech samples extracted from audio recordings collected from the sample members. Multivar iate feature and discriminant analyses were performed on feature vectors re presenting the members of the control and disordered classes. Features deri ved from the formant and power spectral density measurements were found to be the best discriminators of class membership in both the male and female studies. AM features emerged as strong class discriminators of the male cla sses. Features describing F-0 were generally ineffective discriminators in both studies. The results support theories that identify psychomotor distur bances as central elements in depression and suicidality.