主权项 |
1. A device to detect desired audio, comprising:
a ratio calculator, the ratio calculator calculates a ratio between a primary acoustic signal, and a reference acoustic signal, the primary acoustic signal contains desired audio and undesired audio and the reference acoustic signal contains mostly undesired audio, substantially void of undesired audio; a long-term mean value calculator, the long-term mean value calculator is coupled to the ratio calculator, the long-term mean value calculator maintains a running average of the ratio; and a comparator, the comparator is coupled to the ratio calculator and the long-term value calculator, the comparator compares the ratio with the running average, desired audio is detected when the ratio is greater than the running average by a threshold amount. |