Experts of the Central Forensic Science Laboratory recorded the legislator's voice as he has reportedly claimed during the interrogation that the voice in the video footage of his hate speech is not his.
Official said the voice sample would be sent to a laboratory in Chandigarh to match it with the voice in the video footage of the public meeting.
Akbar Owaisi was brought from the district jail in Adilabad to Nirmal, where he was produced before Judicial First Class Magistrate K. Ajesh Kumar. After the recording of voice, the magistrate extended the legislator's judicial custody till Feb 19. The police later shifted him back to jail in Adilabad, about 300 km from here and 90 km from Nirmal.
Akbar Owaisi was arrested Jan 8 for making a hate speech at a public meeting in Nirmal Dec 22. He is since lodged in Adilabad jail. A member of assembly from Chandrayangutta constituency in Hyderabad, he is facing charges of sedition, waging war against the nation and promoting enmity between people.
The MIM leader was also produced before a court in Nizamabad Jan 24 in another case of hate speech booked in that town. A court in Nizamabad is set to pronounce later in the day orders on his bail petition and also on police's request for permission to record his voice.
Why Chandigarh lab
The voice testing department is called the tape authentication and speaker identification (TASI) division. The Central Forensic and Scientific Laboratory, Chandigarh, is one of the sophisticated labs in the country to analyse voice samples. Even though Mumbai too has voice lab there is an acute shortage of staff. the Chandigarh unit is also the country's first laboratory to put in place a mechanism to solve crimes pertaining to voice chats on social networking sites, Skype, Vieber and other such voice communications.
The number of crimes taking place through internet-telephony or Voice Over Internet Protocol, voice chats are on the rise, but so far, no mechanism was available in India to solve these cases.
Voice identification process
In most cases an audio exemplar (audio recording) is created by the audio forensic expert to be used as a comparison to the evidence for the purpose of identification. Unlike the original evidence, the exemplar is created in a controlled environment.
A transcript of the evidence recording is also created to help guide the exemplar recording process. The forensic expert does not notify the accused (defendant) of the portions of the transcript that will be recorded until the scheduled recording time. The reason for this is to have the ability to be spontaneous and unrehearsed when creating the exemplar.
The exemplar comparison call is scheduled between the lawyer, audio forensic expert and the defendant. If the defendant is incarcerated the prison is involved in the coordination so the call can be recorded from the prison.
Its best to have the defendant read each sample three times giving the expert options when conducting the testing. Once a reliable exemplar has been created, the audio expert can begin the voice identification process.
Creating a high quality exemplar under supervision is probably the most important part of the voice identification process. If there are other recorded conversations that include the defendant's voice but are not the exact words used in the evidence recording, they can be used as comparison.
How evidence is evaluated
In case of positive identification: At least 90 percent of all comparable words must be very similar aurally and spectrally, producing not less than twenty matching words. The voice samples must not be more than six years apart.
In case of probable identification: At least 80 percent of the comparable words must be very similar aurally and spectrally, producing not less than fifteen matching words.
In case of possible identification: At least 80 percent of comparable words must be very similar aurally and spectrally, producing not less than ten matching words.
If case of inconclusive outcome: Falls below either the Possible Identification or Possible Elimination confidence levels and/or the examiner does not believe a meaningful decision is obtainable due to various limiting factors.