Dynamic adjustment of noise separation in data handling, particularly voice activation

摘要

Data handling dynamically responds to changing noise power conditions to separate valid data from noise. A reference power level acts as a threshold between dynamically assumed noise and valid data, and dynamically refers to the reference power level changing adaptively with the background noise. The introduction of dynamic noise control in VOX (Voice Activated Transmission) improves a VOX device operation in a noisy environment, even when the background noise profiles are changing. Processing is on a frame by frame basis for successive frames. The threshold is adaptively changed when a comparison of frame signal power to the threshold indicates speech or the absence of speech in the compared frame repeatedly and continuously for a period of time involving plural successive frames having no valid speech or noise above the threshold to correspondingly reduce or increase the threshold by changing the threshold to a value that is a function of the input signal power.