Electrical Network Frequency Analysis
ENF analysis is a technique for validating audio recordings by comparing frequency changes in background mains hum in the recording with long-term high-precision historical records of mains frequency changes from a database. In effect the mains hum signal is treated as if it were a time-dependent digital watermark that can help identify when the recording was created, and help detect any edits in the recording. The technology has been hailed as “the most significant development in audio forensics since Watergate”. This is just one of the powerful tools we use to determine Audio has been Tampered with or edited.