Patent ID: 8170229
Filing Date: 2012-05-01
Classification: G10K,H04M

Abstract:
1. Apparatus for reducing selected sounds comprising: a source for providing source sound waves within a selected band of frequencies; a device for receiving said source sound waves and for generating electrical signals in response to said source sound waves; circuitry for receiving said electrical signals and for generating additional electrical signals representative of said source sound waves, said additional electrical signals being delayed by at least one complete wave cycle (360 degrees) up to ten wave cycles plus about 180 degrees with respect to said electrical signals; and a device for receiving and generating cancellation sound waves in response to said delayed additional electrical signals, and said device positioned such that said cancellation sound waves interfere with said source sound waves, such that said cancellation sound waves at least partially cancel said source sound waves and said source sound waves at least partially cancel said cancellation sound waves.