Forensic Authentication of Mobile Audio Using Electric Network Frequency (ENF)

In this presentation, I discussed the role and importance of utilizing Electrical Network Frequency (ENF) in forensic audio analysis. I explore how ENF signals embedded in audio recordings can be used to authenticate recordings through captured power grid fluctuations that allow for historical comparisons with regional grid frequency databases.

I emphasize ENF's heavy dependence on the recording system, including microphones, analog-to-digital converters, filters, and compression for intelligibility. Many mobile devices suppress or distort ENF signals, make reliable detection inconsistent. As a result, analysis approaches should ideally concentrate on searching for multiple ENF traces, checking phase continuity, and evaluating suspicious regions, all while acknowledging some recordings cannot support any ENF analysis.