Collection of Voice Samples

• A political figure recently came before the Central Bureau of Investigation to provide voice samples for a speech about his suspected role in the 1984 anti-Sikh riots case.
• With the ability to identify individuals and verify evidence, voice samples have grown to be a crucial tool in criminal investigations.

The procedure for gathering voice samples

• In order to obtain consent to record someone's voice for the sake of a case, an investigating agency typically goes to court.
• This type of forensic investigation is employed to support other evidence in the case.
• For a controlled and noise-free setting, a voice sample is typically taken in an echo-proof room using a voice recorder.
• To allow both vowels and consonants in the spoken bit to be alternately assessed, forensic officials employ international phonetic alphabets while capturing a voice sample and ask the subject to pronounce only a short portion of the original remark.

Methods of Comparison:

• When the speaker is identified, both voice samples are confirmed. An anonymous voice sample is compared to a suspect list of five people.
• For simplicity of analysis, recording voices where the subject only pronounces a small portion of the original utterance uses international phonetic alphabets.
• India's forensic laboratories use the semi-automatic spectrographic approach for voice sample.
• If the results of the examination of the voice sample are positive or negative, the forensic lab provides the final report to the investigating agency.
• A likelihood ratio of the voice samples is created using the automatic approach, which is used in some countries. This improves effectiveness.

First Occurrence of Use

• The voice identification analysis method, also known as spectrographic at the time, was originally employed by the US Federal Bureau of Investigation (FBI) in the 1950s, but the process only received official recognition in 1962.

The permissibility of obtaining voice samples

• Given that voice samples are a relatively recent technological innovation, there is no explicit framework for examining them in India's criminal procedure legislation.
• The law contains explicit provisions for the routine collecting of hair and semen samples for DNA analysis and for general body measures. However, in order to acquire voice samples, the police must either go to court or have the accused's permission.
• A doctor may examine the accused at the request of a police officer, according to Section 53 (1) of the Code of Criminal Procedure.
• "The examination of blood, blood stains, semen, swabs in case of sexual offences, vomit and sweat, hair samples, and fingernail clippings by the use of modern and scientific techniques, including DNA profiling and such other tests as the registered medical practitioner thinks necessary in a particular case" is what is meant by "examination" in this provision.
• The phrase "such other tests" is understood in this context to refer to a collection of voice samples.
• The question of whether taking voice samples would violate either the fundamental right against self-incrimination or the right to privacy was examined by the Indian Supreme Court in 2013.
• The Supreme Court ruled in a subsequent three-judge bench hearing that taking a voice sample for an investigation won't infringe the accused's fundamental rights.
• According to its conclusion, the right to privacy cannot be viewed as absolute and must yield to a strong public interest.
• The Punjab and Haryana High Court recently made the observation in a judgement from 2022 that voice samples mimic fingerprints and handwriting, are obtained with permission in line with the law, and are used to compare previously gathered evidence.

Cons:

• If a person's voice is affected as a result of medication or if they have a cold, there may be inaccuracies.
• The expert's method and the court's analysis will determine how credible the sample is.