Forensic Audio

Through the use of equipment and software developed specifically for forensic work we can perform the following services: forensic audio examinations and authentication, scientific examination of recordings for alteration, omissions, editing, tampering, recorder actions (stop / start / pause / voice activation). Analysis determines that a particular machine was capable of making the recording offered in evidence. Originality is examined. Speakers are identified. Voice and non-voice signal analysis is performed and samples are plotted on a spectrum analyzer; waveforms are compared and printed.

Services Offered:

Noise Reduction and Audio Restoration
Noise Reduction is the most requested activity at our lab. Removing hiss, hum, buzz, clicks, pops, and all other audio disturbances, while maintaining speech intelligibility in marginal recordings is a real challenge. In most cases it cannot be done with "off the shelf" software at a recording studio. It requires hardware assisted gear made (not adapted) specifically for forensic enhancement.

Audio Clarification & Audio Evidence Cleanup
Sophisticated computer algorithms identify voice and non-voice content and process the noise out, while enhancing the voice. Intelligibility is greatly improved. Near and far speakers can then be identified. Artifacts introduced by recording and re-recording are removed. Transcriptions can be made and linked to CD copies of the final product. Reports are included, if requested. All enhancement procedures are fully documented.

Audio Editing
If requested, isolation of areas of interest are copied to CD and cross-referenced on a spreadsheet. The spreadsheet can include further information as to tape condition and notes as to problems encountered and strategy for enhancement.

A chain of custody should be maintained for the film, audio or video tape upon which original images are recorded. The chain of custody document identifies individuals who had custody and control of the evidence from the point of capture to archiving. Once the file has been archived, the chain of custody should document the identity of the individuals who had custody and control of the archived image. Immediately after digitizing, we put your original evidence in an evidence locker. We return it to you as soon as possible, by the most secure method available. We work on an exact duplicate of the file and never alter the original.

We are equipped to do audio restorations for all file based digital formats, as well as the following other formats:


  • A.D.A.T.
  • DA-38
  • DA-88
  • MiniDisk
  • D.A.T.
  • Cassette Tape
  • 1/4" - 2 Track Analog Tape (reel to reel)
  • Old School 8 Track (like in cars from back in the day)
  • Vinyl & Shellac Records (with high quality turntables & cartridges)
  • Digital Recording (of any kind)


  • DVC ProHD (small, medium & large formats)
  • Sony HDCAM (small, medium & large formats)
  • Digi-Beta (small, medium & large formats)
  • Mini-DV
  • VHS
  • S-VHS
  • U-Matic