AES New York 2015
Workshop W15
Friday, October 30, 6:00 pm — 7:00 pm (Room 1A22)
W15 - Audio Enhancement: How to Improve the Effectiveness of Cross-Channel Filters by Using Time Compression/Expansion to Maintain Signal Alignment
Chair:Daniel Rappaport, CACI - Annandale, VA, USA
Panelists:
Eddy B. Brixen, EBB-consult - Smørum, Denmark; DPA Microphones
Gordon Reid, CEDAR Audio Ltd - Cambridge, UK
Abstract:
A common forensic audio enhancement request is to attenuate music or a television/radio broadcast from a recording to unmask underlying speech. Traditional equalization and expansion techniques affect the desired target signal as well as the unwanted noise. When a clean reference recording is available, cross-channel adaptive and lattice filters or dynamic spectral subtraction may be used to cancel out the offending signal. Various tools and filters are available for this type of processing, but they all rely on precise alignment of the reference signal to the recording being enhanced. Even with the aid of auto-alignment tools, word clock drift negatively impacts the effectiveness of the filter. This workshop will present a technique to calculate the linear offset and apply time compression/expansion to the reference track, which increases the effectiveness of the filter.
