Electrical network frequency analysis
Appearance
An editor has nominated this article for deletion. You are welcome to participate in the deletion discussion, which will decide whether or not to retain it. |
Electrical network frequency analysis is a forensic science 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.[1][2]
In effec the mains hum signal is treated as if it was a time-dependent digital watermark that can be used to identify the time at which the recording was created, and to help detect any edits in the sound recording.[3]
According to a paper by Huijbregtse and Geradts, the ENF technique, although powerful, has significant limitations caused by self-similarity within the mains frequency database, particularly for recordings shorter than 10 minutes.[4]
References
- ^ Chris Williams (2010-06-01). "Met lab claims 'biggest breakthrough since Watergate'". The Register.
- ^ Catalin Grigoras. "Digital Audio Recording Analysis: The Electric Network Frequency Criterion" (PDF). Diamond Cut Productions, Inc.
- ^ Cooper, A.J: "The electric network frequency (ENF) as an aid to authenticating forensic digital audio recordings – an automated approach"., Conference paper, AES 33rd International Conference, USA (2008)
- ^ Maarten Huijbregtse, Zeno Geradts. "Using the ENF criterion for determining the time of recording of short digital audio recordings" (PDF). Netherlands Forensic Institute, Departement Digital Evidence and Biometrics. Retrieved 2010-06-06.