Is Kareena Kapoors voice as attractive as she is?
New Delhi, July 28: A team of Indian scientists chasing the secrets of sexually appealing voices has identified a mathematical feature in vocal chord vibrations that could inject greater objectivity in the task of rating human voices.
Speech and language pathologists at the Kasturba Medical College in Mangalore have analysed voice waveforms of men and women and shown that a feature linked to the frequency makes human voices either more or less sexually-appealing.
Weve found something tied to sexually attractive voices that we can measure, said Jayashree Bhat, the head of audiology and speech language pathology at the KMC. The findings will appear in a forthcoming Journal of Voice. While the voice helps provide a unique identity to a person, it is also among the things that can make a person appear attractive, Bhat said.
Research studies conducted in the US since the late 1980s have suggested that people with attractive voices are perceived more favourably and seen as having desirable personality traits such as warmth or honesty.
In one study published in Evolution and Human Behaviour in 2004, psychologist Susan Hughes and her colleagues discovered a relationship between the quality of voice and sexual behaviour, implying that voice may be evolutionarily linked to mate choice.
At the KMC, the researchers used commercial voice analysis software to examine voice waveforms representing the vocal chord movements of people during normal speech and found that a feature called cepstral peak prominence was linked to attractive voices.
The greater the CPP value, the more attractive the voice, said KMC researcher Radish Balasubramanium, the studys lead author. The CPP is a measure of the number of times that harmonics, or multiples of the fundamental frequency at which vocal chords vibrate, occur during speech, Balasubramanium said. For men the fundamental frequency typically lies between 90 and 140 per second, for women it is between 180 and 240.
The KMC findings are consistent with earlier research that had suggested that hormones that determine sex-specific body features also influence voice. A French research team had even shown a decade ago that harmonics in voice depend on sex hormones.
While the CPP has earlier been used to study voice disorders, the new study for the first time correlates it with sexually appealing voices," said Suja Kunnath, a speech language pathologist at the National Institute of Speech and Hearing in Thiruvananthapuram, who was not connected with the study. This opens up the possibility of using the CPP as a measurable tool to evaluate voices, Kunnath told The Telegraph.
The KMC researchers asked 100 Malayalam-speaking male and female volunteers to speak sentences in their normal voices and asked three judges who did not understand a word of Malayalam to rate their voices for attractiveness on a scale of 1 to 5.
We picked judges who did not know Malayalam so that the content or meaning of what the voices spoke would not influence them, Balasubramanium said.
The experiments were repeated over several days and a set of 28 female and 39 male voices were rated sexually attractive by all the three judges consistently over several cycles of listening.
The KMC researchers say this line of research is intended to help introduce quantification in the assessment of human voices for attractiveness. Currently we use objective voice analysis mainly for studying voice disorders, Bhat said. We were surprised — although we had a small sample, the CPP seems like an efficient tool to delineate sexually attractive voices. But there may be other parameters too, she said.
Balasubramanium said future studies at the KMC would try to correlate CPP values with professional voice users such as singers as well as seek out other parameters linked to attractive voices.
In the US, studies have indicated that voice attractiveness may also be linked to body configurations linked to attractiveness. The 2004 study by the US psychologist Hughes, currently at Albright College, had found links between voice attractiveness and sexual behaviour — both males and females whose voices were rated attractive had sex at an earlier age and had more sexual partners.
Cultural differences, of course, will influence the findings of such studies, Balasubramanium said.