Affective State and Voice

Human speech is considerably influenced by the affective state of the speaker, such as sadness, happiness, fear, anger, aggression, lack of energy, or drowsiness. Attentive listeners discover a lot about the affective state of his conversational partner without having to talk about it explicitly. Low mood reduces the dynamic expressiveness of human voices, thus reducing the inter-individual differences regarding speaking behavior and voice sound characteristics. In consequence, the voices of people in the state of low mood become similar to each other ("depressive voices"). During recovery, however, speaking behavior and voice sound characteristics return to "normal" values.

Speaking Behavior and Voice Sound Characteristics

Speech characteristics can be roughly described by a few major features: speech flow, loudness, intonation and intensity of overtones. Speech flow describes the speed at which utterances are produced as well as the number and duration of temporary breaks in speaking. Loudness reflects the amount of energy associated with the articulation of utterances and, when regarded as a time-varying quantity, the speaker's dynamic expressiveness. Intonation is the manner of producing utterances with respect to rise and fall in pitch, and leads to tonal shifts in either direction of the speaker's mean vocal pitch. Overtones are the higher tones which faintly accompany a fundamental tone, thus being responsible for the tonal diversity of sounds.

Learning to Recognize: Normative Studies with Healthy Subjects

The «Institute for Response-Genetics (IFRG)», University of Zurich (Switzerland), has carried out 6 studies with healthy volunteers from Bristol (English: n=117), Lausanne (French: n=128), Zurich (German: n=208), Valencia (Spanish: n=124), Milano (Italian: n=120), and Argentina (Spanish: n=117) in order to investigate (1) the inter-individual scattering of speech parameters; (2) the intra-individual stability of speech parameters over time; (3) the influence of spoken language; and (4) the influence of the factors age, sex, and education. A specific study design with different types of spoken text along with repeated assessments at 14-day intervals was used to estimate the "natural" fluctuations of speech parameters as a function of spoken language, gender, age, and education [learn more ...].

Self-Assessment Voice Analysis System (Biofeedback)

Based on comprehensive normative data the «Institute for Response-Genetics (IFRG)», University of Zurich (Switzerland), has developed an easy-to-use, self-assessment voice analysis system for Laptops, Tablets, Smartphones, and iPhones. In the sense of biofeedback, this system ("voice app") provides directly interpretable results when (1) monitoring general health and well-being; (2) monitoring the effects of chronic stress; (3) learning to better cope with chronic stress; and (4) monitoring the risk of depression and doing something about it where necessary [see our scientific article].