Designed to remove noise from monophonic signals, single channel adaptive filters and often the tools of choice for the law enforcement and security communities. Those in CEDAR Cambridge offer filter lengths of up to 100,000 taps with user control of the length up to one second. The user has control over the Attack (and, on the adpative filter, the Release) constant, and the filter coefficients are displayed graphically to help the user determine the optimum settings for each job.
There are two output modes provided: the predicted signal, and the filtered signal. You can vary the output mix between the original audio and either of these to maximise the intelligibility of the result.
The Adaptive Filter removes many forms of interference and background noise, making speech signals more listenable and more intelligible, aiding transcription and making recordings more presentable for the courtroom and juries.
A more powerful filter than the Adaptive Filter, the Lattice Filter digs deeper into a noisy recording and is capable of extracting more fricative sounds and consonants that would otherwise be buried in broadband noise.
Forensic overview