US 11,790,931 B2
Voice activity detection using zero crossing detection
Roger David Serwy, Austin, TX (US)
Assigned to Ambiq Micro, Inc., Austin, TX (US)
Filed by Ambiq Micro, Inc., Austin, TX (US)
Filed on Oct. 27, 2020, as Appl. No. 17/81,378.
Prior Publication US 2022/0130410 A1, Apr. 28, 2022
Int. Cl. G10L 25/09 (2013.01); G10L 15/10 (2006.01); G10L 15/02 (2006.01)
CPC G10L 25/09 (2013.01) [G10L 15/02 (2013.01); G10L 15/10 (2013.01)] 15 Claims
OG exemplary drawing
 
1. An apparatus comprising:
a processing device programmed to:
receive an original audio signal;
add a high-frequency signal to the original audio signal to obtain an audio signal, the high-frequency signal having a frequency and amplitude selected to add zero crossings to portions of the original audio signal including only ambient noise without speech;
generate a pulse stream according to zero crossings detected in the audio signal;
generate a pulse density stream according to the pulse stream indicating frequency of occurrence of pulses in the pulse stream over time;
evaluating the pulse density stream with respect to a threshold condition; and
identifying speech portions of the audio signal corresponding to portions of the pulse density stream meeting the threshold condition.