NCJ Number
155222
Journal
Journal of Forensic Identification Volume: 45 Issue: 3 Dated: (May/June 1995) Pages: 250-258
Date Published
1995
Length
5 pages
Annotation
This report describes and tests a technique for recording and processing cordless telephone conversations, so as to improve the intelligibility of such calls.
Abstract
The recording and processing technique separates the two sides of cordless telephone conversations and their associated background noises. The signal used for testing was a cordless phone call to a movie schedule recording, using a Panasonic Easa- Phone. During the call, one researcher talked over the movie announcer. The audio was recorded on a consumer-quality Sanyo RDW41 cassette recorder from two Realistic PRO-4006 scanners. The recorded signals were sampled and played back with a Multi-sound Multimedia-PC audio board installed in a Gateway 2000 4DX2-50V personal computer. The intelligibility and quality of the resulting signals were significantly improved by using the described adaptive digital filtering techniques to separate the two sides of the telephone conversations. The processed signals were appropriate for transcription, analysis, further enhancement, or courtroom presentation. 1 table, 2 figures, and 5 references