Patent ID: 7536301

Claim:
A device, comprising; a noise state estimator to monitor an audio signal, estimate a level of background noise in the audio signal, and output the estimate of the level of background noise; a static offset generator coupled to said noise state estimator to receive the estimate of the level of background noise, apply an offset from the estimate of the level of background noise to form a static threshold, and output the static threshold; a dynamic offset generator to generate a dynamic offset from a post-trigger level of background noise and output the dynamic offset from the post-trigger level of background noise; circuitry coupled to said static offset generator and said dynamic offset generator to receive the static threshold and the dynamic offset from the post-trigger level of background noise, add the dynamic offset from the post-trigger level of background noise to the static threshold to form an adaptive threshold, and output the adaptive threshold; and an audio signal/adaptive threshold (AS/AT) comparator to compare the audio signal to the adaptive threshold and generate a trigger signal if a magnitude of the audio signal is greater than a magnitude of the adaptive threshold.