Adaptive spectral subtraction for superior active noise and interference cancellation.

Advanced microphone arrays, low noise.  Tibbetts, Knowles.

Audio pre-amplifiers. Audio power amplifiers with ultra-low power consumption.

Adaptive distortion correction.

Adaptive beamforming microphone arrays, digital control.

Acoustic Echo Cancellation experts.

Active Noise Cancellation.

Surveillance microphones.

Digital lossless and lossy compression algorithms (SPEEX etc)

Spectral analysis, editing.