Archived from groups: rec.audio.tech (More info?)
FYI...
O-1 An Improved Method of Noise Cancellation—David Herman1, Dudley
Haestler1, Simon Busbridge2
1 AudioGravity Ltd., Hove, UK;
2 University of Brighton, Brighton, East Sussex, UK
The effectiveness of conventional noise cancellation techniques is
limited by tolerances between the signal and noise channels. A system
is described in which the ambient noise error signal is fed back for
further cancellation (Advanced Ambient Noise Rejection Technology,
ANRT). Small physically displaced microphones differentiate near-
field signals from high-level ambient noise. Band limiting filters
further reduce high-frequency phase distortion. The effectiveness is
increased such that an unintelligible signal produced by normal speech
can result in an SNR improvement of 40 dB in an ambient noise field of
98 dBA. The technology can be integrated into a single, small,
low-power CMOS analog integrated circuit; it is also ideally suited
for MEMS (Si-Mic).
....Moose
FYI...
O-1 An Improved Method of Noise Cancellation—David Herman1, Dudley
Haestler1, Simon Busbridge2
1 AudioGravity Ltd., Hove, UK;
2 University of Brighton, Brighton, East Sussex, UK
The effectiveness of conventional noise cancellation techniques is
limited by tolerances between the signal and noise channels. A system
is described in which the ambient noise error signal is fed back for
further cancellation (Advanced Ambient Noise Rejection Technology,
ANRT). Small physically displaced microphones differentiate near-
field signals from high-level ambient noise. Band limiting filters
further reduce high-frequency phase distortion. The effectiveness is
increased such that an unintelligible signal produced by normal speech
can result in an SNR improvement of 40 dB in an ambient noise field of
98 dBA. The technology can be integrated into a single, small,
low-power CMOS analog integrated circuit; it is also ideally suited
for MEMS (Si-Mic).
....Moose