Voice Activity Detection is a technique used in speech processing wherein the presence or absence of human speech is detected in regions of audio. The main uses of VAD are in speech coding and speech recognition. It can facilitate speech processing, and can also be used to deactivate some processes during non-speech segments: it can avoid unnecessary coding/transmission of silence packets in VOIP, saving on computation and on network bandwidth.

VAD is an important enabling technology for a variety of speech-based applications. Therefore various VAD algorithms have been proposed that provide different compromises between latency, sensitivity, accuracy and computational cost. Some VAD algorithms also provide further analyses, for example whether the speech is voiced, unvoiced or sustained. Voice activity detection is usually language independent.

Answered by kshitij.ganekar , an ibibo Citizen, at 10:15 PM on June 26, 2009

Voice activity detection (also known as speech activity detection or, more simply, speech detection) is a technique used in speech processing wherein the presence or absence of human speech is detected in regions of audio (which may also contain music, noise, or other sound) [1]. The main uses of VAD are in speech coding and speech recognition. It can facilitate speech processing, and can also be used to deactivate some processes during non-speech segments: it can avoid unnecessary coding/transmission of silence packets in VOIP, saving on computation and on network bandwidth.

VAD is an important enabling technology for a variety of speech-based applications. Therefore various VAD algorithms have been proposed that provide different compromises between latency, sensitivity, accuracy and computational cost. Some VAD algorithms also provide further analyses, for example whether the speech is voiced, unvoiced or sustained. Voice activity detection is usually language independent.

Answered by Sheik Sharfu , an ibibo Citizen, at 1:19 AM on June 26, 2009

visit this link u may get answer http://en.wikipedia.org/wiki/Voice_ activity_detection

Answered by Hemanth Kuma , an ibibo Citizen, at 9:21 PM on June 25, 2009

VAD Voice Activity Detector

Answered by bindasrajeev , an ibibo Citizen, at 8:07 PM on June 25, 2009

VAD Voice activity detection (also known as speech activity detection or, more simply, speech detection) is a technique used in speech processing wherein the presence or absence of human speech is detected in regions of audio (which may also contain music, noise, or other sound) . The main uses of VAD are in speech coding and speech recognition. It can facilitate speech processing, and can also be used to deactivate some processes during non-speech segments: it can avoid unnecessary coding/transmission of silence packets in VOIP, saving on computation and on network bandwidth.

VAD is an important enabling technology for a variety of speech-based applications. Therefore various VAD algorithms have been proposed that provide different compromises between latency, sensitivity, accuracy and computational cost. Some VAD algorithms also provide further analyses, for example whether the speech is voiced, unvoiced or sustained. Voice activity detection is usually language independent.

It was first investigated for use on time-assignment speech interpolation (TASI) systems

Answered by Manoj , an ibibo Specialist, at 7:28 PM on June 25, 2009

voice activity detection

Answered by TARUN KUMAR , an ibibo Citizen, at 7:14 PM on June 25, 2009

Voice activity detection (also known as speech activity detection or, more simply, speech detection) is a technique used in speech processing wherein the presence or absence of human speech is detected in regions of audio (which may also contain music, noise, or other sound). The Voice Activity Detection (VAD) algorithm analyzes voice activity to detect silence intervals.

VAD is successfully applied in numerous applications of speech technologies (particularly in mobile communications, robust speech recognition or digital hearing aid devices). Various VAD algorithms have been proposed that provide different compromises between latency, sensitivity, accuracy and computational cost.

The typical design of a VAD algorithm is as follows:

1. There may first be a noise reduction stage, e.g. via spectral subtraction.
2. Then some features or quantities are calculated from a section of the input signal.
3. A classification rule is applied to classify the section as speech or non-speech - often this classification rule is whether the calculated value(s) exceed certain threshold(s).

See also these pages below:

http://en.wikipedia.org/w iki/Voice_activity_detection

htt p://www.hindawi.com/journals/asp/20 05/561951.abs.html

http://focus. ti.com/general/docs/lit/getliteratu re.tsp?literatureNumber=sprs018a&fi leType=pdf.

http://cvsp.cs.ntua. gr/projects/pub/HIWIRE/HiwirePublic ations/gorrizicslp06.pdf

Answered by Vignesh Babu , an ibibo Advisor, at 7:12 PM on June 25, 2009