Patent ID: 9094744
Filing Date: 2015-07-28
Classification: G10K,H04R

Abstract:
1. In a portable device including at least a first microphone and a second microphone receiving sounds in the vicinity of the portable device and outputting audio signals, each of the at least first and second microphones being located on the portable device at different distances respective to a talker's mouth in ordinary operation, and a noise cancellation circuit, a close talk detector, comprising: a power level detector, coupled to the at least first and second microphones, receiving the audio signals from the at least first and second microphones, measuring power levels of the audio signals from the first and second microphones, and comparing the power levels from the at least first and second microphones to produce a ratio of the power levels of the at least first and second microphones; and a comparator for comparing the ratio of the power levels of the at least first and second microphones to a predetermined threshold and detecting close talk if the ratio of the power levels of the at least first and second microphones exceeds the predetermined threshold, wherein the comparator outputs a signal to the noise cancellation circuit to alter updating of the noise cancellation circuit when the close talk is detected to prevent the noise cancellation circuit from adapting to the talker's voice.