LARGE SCALE TEST OF DIGITAL AUDIO FILE STRUCTURE AND FORMAT FOR FORENSIC ANALYSIS

This paper presents an extensive study on MP3, WAV and WMA file structure and format analysis for forensic purposes. It is common nowadays for the authenticity of digital audio recordings to be challenged either before being accepted as evidence in legal proceedings or in ascertaining the veracity of a unknown file's meaning. The framework for forensic authentication of digital audio includes the structure and format analysis that requires the investigation of the suspected recording device as well. Sometimes the suspected recorder is not available for test reference recordings which could lead some labs to reject the request for analysis. This paper presents the analysis of audio files collected over an 18-year span from more than 125 digital audio recorders and 40 commercially available software applications. It also explains the principles that can be followed to collect reference samples, build and maintain reference databases for forensic analysis, and use them in real cases when the suspect recorder is not available.