Patent ID: 6603858
Filing Date: 2003-08-05
Classification: H04R

Abstract:
An apparatus for processing sound comprisinga) an array of microphones; b) first and second array processors coupled to said array, each of said processors arranged to produce a characteristic total noise output being a function of ambient noise, the first processor being arranged to produce a lower characteristic total noise output than the second processor over a first range of values of said noise, and the second processor being arranged to produce a lower characteristic total noise output than the first processor over a second range of values of said said noise; c) a noise floor indicating circuit coupled to at least one microphone of said array of microphones arranged to produce a noise floor signal indicative of said ambient ambient noise; d) control means coupled to said noise floor indicating circuit and arranged to produce first and second control signals indicating when said ambient noise signal is in said first range of values or in said second range of values; e) first and second variable gain means, the first and second variable gain means being coupled to the first and second microphone array processor, and being responsive to the first and second control signal respectively, the first and second variable gain means arranged to apply variable gain to the characteristic total noise output of the first and second array processor, respectively the control means and said first and second variable gain means being further arranged so that the gain applied by the first variable gain means is greater than the gain applied by the second variable gain means when said ambient noise signal is within said first range and the gain applied by the second variable gain means is greater than the gain applied by the first variable gain means when said ambient noise is within said second range.