First of all, one of the most basic aspects is to collate the voices. It is a simple but effective technique in which the voice of the original recording is compared with another with the voice of the person or persons involved, analyzing digital aspects such as the comparison of the different acoustic parameters.
The analysis of conversations is another of the most fundamental tasks of audio expertise. It consists of the study of these when the voices are stepped on or if conversations were deliberately overlapped in order to hide something.
Determine in any type of audio the existence of indicators that confirm if the audio has been modified or manipulated.The ambient sound is another key factor that will help to check if the audio has been cut since, obviously, if it has cuts it is because it has been manipulated.
What Must Be Taken Into Account To Present An Audio As Valid Evidence In A Trial?
An audio test can become a determining factor when tipping the balance before a jury. However, it will be necessary to certify said audios by means of a forensic audio specialist report in order to certify their authenticity. In the same way, the file has to be heard clearly, so the expert will have to work on cleaning the segment of interest.
And finally, it must also be confirmed, in the aforementioned expert report, that the recording has not been manipulated since its recording through the use of editing software tools.
What Kind Of Recordings Are Accepted As Expert Evidence In A Trial?
In recent years, the need to validate audio recordings for legal proceedings has increased remarkably. We live constantly connected to our smartphones, tablets or computers. For this reason, the law has had to adapt when it comes to accepting the presentation of audios as evidence in all kinds of disputes. A WhatsApp audio file or the recording of a phone call can become crucial evidence for the resolution of a case.
However, not all audio files are accepted as evidence, since if, for example, for the confession of a crime, a scenario has been prepared for a person to confess to the commission of a crime, this recording will not be accepted before a court. Only audio files with spontaneous confessions are accepted as evidence.
Why Is Our Voice So Important? The Biometric Parameter And The Personal Identification Mark
Biometric parameters are an element that is increasingly used as a complement to new technologies. The use of fingerprints to activate an electronic device or the retina scanner are some examples that show this and that little by little are beginning to be incorporated into our reality. The same happens with the voice, which can be decisive for personal identification.
Thus, for example, the concept of a voice passport is not new within the branch of criminalistics and forensic acoustics. This is an essential technique for police investigations that allows determining the profile of the person speaking, evidencing parameters such as age, sex, social stratum, geographical origin, emotional state or even certain pathologies of the speaker. It also allows for comparative analysis of voice and speech, so that full identification of that person is established.
As with other technological innovations, these applications originally restricted to a specific field are beginning to form part of our daily lives. In teleworking contexts, where the importance of telematics means is evident, there are already companies that allow voice signatures, that is, a voice signature system that replaces the handwritten signature and is fully legally valid.
These are just a few examples of the value that voice has in certain circumstances, which will increase as all these technologies are integrated into everyday life. However, at present, voice expertise is already an extremely valuable resource in the judicial field.
The advancement of forensic technology, along with these forgeries, is essential to determine the use of synthetic voices and can detect their inauthenticity by analyzing different parameters, such as speech speed, which are determining factors in recognizing the use of false voices.