Know the process of how audio forensics do their work
Like digital forensics, audio forensics includes analyzing, identifying, acquiring, and checking sound recordings. These sound recordings will show evidence of criminal or fraudulent activity in a court of law. It is carried out by audio forensic experts, who help law officials solve cases and assist with private or public investigations. Audio forensics’ goal includes audio evidence authenticity. By boosting the audibility of low-level sounds and interpretation of conversations, it helps to give information about the accidents or crime scene. Modern equipment is used to bring out this process, but there are now forensic audio enhancement services to help you.
Authentication
The events’ authenticity will show the recording’s integrity and whether or not the recording has been tampered with. In the digital audio, edits can be done and covered easily. There are free versions of audio editing software that you can get online to change the conversations in the digital audio recording. When the parties in litigation believe that the recording is tampered with, an audio forensic expert will check the recording. The first thing is to do a chain of custody when they will authenticate the audio recording. Audio evidence must be more authentic and kept in a digital audio recorder.
Visual inspection
Visually checking the audio waveform and spectrogram is the best step in authenticating the audio. It will be manageable with the electronic measurement as the expert has the properties and information. When there are sudden breaks in the recording waveform, these are the signs of editing. The expert must focus on the phasing of the waveform. It can be seen when you zoom in on the waveform of the recording where it is inverted, as it also means there was an edit. The spectrogram shows the frequency spectrum with colder or warmer colors that show the strength. The noise floor can be seen, which helps to know the brakes in the sound. All the recordings have noise floors, even if they are pretty inaudible. Any breaks can be a sign of an edit when you check the spectrogram. Any changes in the volume of the noise floor can be a sign of an improvement.
Critical listening
It is the step to be familiar with the audio evidence, whether there is an edit during the phase. There will be abrupt changes where detecting them takes a lot of work. The experts must put themselves in an isolated room during the listening, which will avoid any outside disturbances. The quiet environment improves the critical listening focus. Professional-grade monitoring headphones and high-quality studio monitors are the best for audio recordings. The investigators will use professional-quality headphones and speakers with the flattest frequency response. It means they will make natural and neutral sounds. It is necessary for the forensic expert because it increases and cuts in frequencies that can affect the analysis of the audio recording.
Audio recordings secure from crime scenes or accidents are sent to forensic labs for evaluation. They will be the ones to give strong evidence to the authorities in a court hearing. When looking for a professional audio forensic expert, you will know their process and have an idea about it.
