Patent ID: 7751575

Claim:
A microphone system for communication devices comprising: a. a first input sound port that leads into a first omnidirectional microphone element; b. a second input microphone port that leads into a second omnidirectional microphone element positioned near the first microphone element; and c. a signal flow processor electrically connected to the first and second microphone elements; wherein the signal flow processor provides an electrical time delay (“τ”) only to the first microphone element and provides a compatible amplitude gain to the second microphone element; wherein τ=(w−u)/c, the variable “w” equals the distance between the receiver and the second sound port, the variable “c” equals approximately 345,000 millimeters per second, and the variable “u” equals √{square root over ( )}[w 2 +d 2 2 −2 d 2 w cos(κ−Ψ)] with the variable “d 2 ” being equal to the distance between the first and second input sound ports, with the variable “κ” being equal to the angle of an ear reference point adjacent to the receiver and the second input sound port, and with the variable “Ψ” being equal to the angle of the first input sound port and the second input sound port; and wherein the signal flow processor subtracts the outputs of the first and second microphone elements to create a null that reduces external acoustic coupling.