Audio Enhancement and Authenticity

AVFL’s President, Robert W. Sanderson and associates are highly trained audio engineering professionals. During his career Rob has been responsible for building and operating world class recording facilities. Now 100% focused on forensic work, Rob brings his training, talented ears and intuitive engineering skills to criminal and civil investigation.

Forensic Audio Services:

Through the use of equipment and software developed specifically for forensic work we can perform the following audio enhancement and authenticity services;

Forensic Audio Examinations and Authentication

Scientific Examination of recordings for alteration, omissions, editing, tampering, recorder actions ie. 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. Voiceprint Identification examinations conducted.

Noise Reduction and Audio Restoration

Noise Reduction. This is the most requested activity at our lab. Removing hiss, hum, buzz, clicks, pops, and all other audio disturbances, while maintaining speech intelligability in marginal recordings is a real challenge. In most cases it cannot be done with “off the shelf” software or at a recording studio. It requires hardware assisted gear made (not adapted) specifically for forensic enhancement. A skilled, experienced operator trained on the equipment at the factory is a must! We provide this “AAA” level of service.

Audio Clarification. and audio evidence cleanup. Sophisticated computer algorithems identify voice and non-voice content and process the noise out while enhancing the voice. Intelligability 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 the strategy for enhancement. Redaction of words, phrases or sounds in audio video files.