Dynamic adjustment of noise separation in data handling, particularly voice activation
View Patent ↗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.
1. A method for managing a transmitter, comprising:
defining a reference level time period;
receiving an input signal including noise and possibly a signal of interest;
calculating a reference level as a function of the power of a first portion of the input signal over the reference time period;
calculating power of a portion of the input signal subsequent to the first portion;
comparing the power of the subsequent portion of the input signal with the reference level;
conducting a transmitter activation determination whether said comparison satisfies a transmitter activation condition, the transmitter activation condition determining whether the power of the subsequent portion of the input signal exceeds the reference level thereby indicating the presence of the signal of interest;
generating an activation signal for activating the transmitter when the transmitter activation condition is satisfied to transmit the signal of interest;
conducting a reference level adjustment determination whether the comparison satisfies a reference level adjustment condition, the reference level adjustment condition testing whether there is a lack of a transition between the presence of the signal of interest in the input signal and the absence of the signal of interest in the input signal for a predetermined time period; and
adjusting the reference level when said reference level adjustment condition is satisfied.
2. The method of claim 1 , for a voice activated transmission, further comprising:
dividing the input signal into a succession of voice signal frames; and
processing the input signal on a frame by frame basis.
3. A computer readable storage media having computer readable code implementing a method for voice activated speech transmission that is dynamically adaptive to a level of noise mixed with valid speech in the input signal, the code including statements for perfonmiing the method of claim 2 .
4. A computer readable storage media having computer readable code implementing a method for activation that is dynamically adaptive to a level of noise mixed in the input signal, the code including statements for perfomming the method of claim 2 .
5. A computer readable storage media having computer readable code implementing a method for activation that is dynamically adaptive to a level of noise mixed in the input signal, the code including statements for performing the method of claim 1 .