AI Glossary

AI Termcirca 2001· Added Aug 12, 2026

Voice Activity Detection

Technology used to identify when a person is speaking versus when they are not.

Voice Activity Detection (VAD) is a critical component of speech recognition systems, as it helps to filter out non-speech audio and improve the accuracy of speech-to-text transcription. VAD algorithms analyze audio signals to determine whether they contain speech or other types of audio, such as background noise or music. This technology has numerous applications, including voice assistants, voice-to-text messaging, and automated customer service systems.

Examples

  • Google Assistant uses VAD to detect when a user is speaking a voice command
  • Zoom uses VAD to automatically transcribe spoken words during meetings

Common misconceptions

  • VAD is the same as speech recognition
  • VAD only works for loud or clear speech

Also known as: Speech Detection, Voice Detection

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