Voice Activity Detector
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Voice Activity Detector w/ Accelerator takes an input signal and tracks the signal level compared to the noise floor. The Modulation Index is then later used to determine if speech is present or not
Input:
Output:
EnvelopeOut: Smoothed envelope of input signal
TopTracker: Signal tracker of the peak of the EnvelopeOut
BottomTracker: Signal tracker of the noise floor of the EnvelopeOut
ModulationIndex: Modulation level of input signal (TopTracker ? BottomTracker)
Parameter Control:
LPF Smoother: 1st order LPF frequency cutoff in Hz for smoothing of input signal
Top Attack:
dB/sec attack time constant value for the TopTracker
Top Release:
dB/sec release time constant value for the TopTracker
Bottom Attack:
dB/sec attack time constant value for the BottomTracker
Bottom Release:
dB/sec release time constant value for the BottomTracker
Top Wait: Time in seconds to wait for TopTracker to be in release mode, before accelerating/increasing the release time
Top Factor: Scalar used to accelerate the release time for TopTracker
Bottom Wait: Time in seconds to wait for BottomTracker to be in attack mode, before accelerating/increasing the attack time
Bottom Factor: Scalar used to accelerate the attack time for BottomTracker
Description:
The VAD w/ Accelerator provides extra conditions to accelerate or increase the time constants in voice detection. Either the Release time for TopTracker is affected or the Attack time for BottomTracker is affected when their corresponding conditions are met. Thus, if TopTracker has been in release mode for Top Wait time, then the Top Release time constant will be increased by a scalar of Top Factor. And if BottomTracker has been in attack mode for Bottom Wait time, then the Bottom Attack time constant will be increased by a scalar of Bottom Factor.