Voice analysis to nail criminals now

The All India Institute of Speech and Hearing (AIISH) has come up with a forensic voice analysis technology that detects voice patterns and helps investigating authorities identify criminals.

The forensic voice analysis technology, which has come of age, will help establish the identity of culprits involved in kidnapping, bribe and murder. “Suppose one receives a threatening call, the voice can be recorded and analyzed and a comparison can be made with the others”, said Vijaylakshmi Basavaraj, Director of AIISH located at Mysore near here.

The analysis is carried out through a spectrograph or a voice pattern, which is three-dimensional. So far, a total of thirteen criminal cases had been referred to AIISH from investigating agencies in Kerala, Chandigarh, Tamil Nadu, Hyderabad, besides Karnataka. The CBI has also sent a case to AIISH.

Head of Department of Speech and Language Research, AIISH, S R Savithri said voice is essentially the outcome of the amount of air released from a person’s mouth after it has passed through the vocal folds. “The tongue, lips and oral cavity, both in shape and volume, starting from the vocal chords to the lips, have a major role to play in the production of sound”, she said.

Forensic voice analysis technology had advanced so much that voice analysis can be completed in a week’s time. Voice prints can be analyzed accurately upto 67 per cent, Savithri said.

When the tape with the recorded voice is sent to the Institute, it is first transcribed and others involved in the case are required to speak the same content. “This is then compared with the recorded voice. Even if people use hankies on the mouthpieces of telephones or put pebbles in their mouth to alter their voice, it really does not affect the analysis because it is based on pronunciation, which comes by way of habit”, Savithri said.