Depressed people may not sing the blues. But they do speak 'em.
Voice tone and speech rate are good objective indicators of the severity of a person's depression, report psychologist Peter J. Snyder and colleagues at the University of Connecticut. And that makes them good signals for monitoring the progress of treatment.
In an exacting study of seven patients, the researchers analyzed the audio portion of videotaped interviews widely used to test for the presence of depressive symptoms and assess their severity. Researchers found that the depression ratings based on content of the interviews correlated with acoustic measures of patient utterances, especially rate of speaking and pitch variability. The slower, more monotone a voice, the more severe the depression.
Acoustical analysis is more definitive in gauging the severity of depression than in diagnosing depression, says Snyder, as there are many reasons that people speak slowly or in a monotone voice. But once a diagnosis of depression is made, he observes in Brain and Cognition, voice analyses can accurately track improvement.
