vapi4k-core/com.vapi4k.dsl.assistant/VoicemailDetectionProperties/machineDetectionSpeechEndThreshold

machineDetectionSpeechEndThreshold

abstract var machineDetectionSpeechEndThreshold: Int(source)

The number of milliseconds of silence after speech activity at which point the speech activity is considered complete. Default is 1200 milliseconds.
Increasing this value will typically be used to better address the short voicemail greeting scenarios. For short voicemails, there is typically 1000-2000ms of audio followed by 1200-2400ms of silence and then additional audio before the beep. Increasing the MachineDetectionSpeechEndThreshold to ~2500ms will treat the 1200-2400ms of silence as a gap in the greeting but not the end of the greeting and will result in a machine detection. The downsides of such a change include:

  • Increasing the delay for human detection by the amount you increase this parameter, e.g., a change of 1200ms to 2500ms increases human detection delay by 1300ms.
  • Cases where a human has two utterances separated by a period of silence (e.g. a "Hello", then 2000ms of silence, and another "Hello") may be interpreted as a machine.
    Decreasing this value will result in faster human detection. The consequence is that it can lead to increased False Human (detected human, actually machine) detections because a silence gap in a voicemail greeting (not necessarily just in short voicemail scenarios) can be incorrectly interpreted as the end of speech.
    Check the Twilio docs for more info.
    @default 1200