Configuration for turn detection, ether Server VAD or Semantic VAD. This can be set to null to turn off, in which case the client must manually trigger model response. Server VAD means that the model will detect the start and end of speech based on audio volume and respond at the end of user speech. Semantic VAD is more advanced and uses a turn detection model (in conjuction with VAD) to semantically estimate whether the user has finished speaking, then dynamically sets a timeout based on this probability. For example, if user audio trails off with "uhhm", the model will score a low probability of turn end and wait longer for the user to continue speaking. This can be useful for more natural conversations, but may have a higher latency.

interface TurnDetection {
    create_response?: boolean;
    eagerness?:
        | "low"
        | "medium"
        | "high"
        | "auto";
    interrupt_response?: boolean;
    prefix_padding_ms?: number;
    silence_duration_ms?: number;
    threshold?: number;
    type?: "server_vad" | "semantic_vad";
}

Properties

create_response?: boolean

Whether or not to automatically generate a response when a VAD stop event occurs. Not available for transcription sessions.

eagerness?:
    | "low"
    | "medium"
    | "high"
    | "auto"

Used only for semantic_vad mode. The eagerness of the model to respond. low will wait longer for the user to continue speaking, high will respond more quickly. auto is the default and is equivalent to medium.

interrupt_response?: boolean

Whether or not to automatically interrupt any ongoing response with output to the default conversation (i.e. conversation of auto) when a VAD start event occurs. Not available for transcription sessions.

prefix_padding_ms?: number

Used only for server_vad mode. Amount of audio to include before the VAD detected speech (in milliseconds). Defaults to 300ms.

silence_duration_ms?: number

Used only for server_vad mode. Duration of silence to detect speech stop (in milliseconds). Defaults to 500ms. With shorter values the model will respond more quickly, but may jump in on short pauses from the user.

threshold?: number

Used only for server_vad mode. Activation threshold for VAD (0.0 to 1.0), this defaults to 0.5. A higher threshold will require louder audio to activate the model, and thus might perform better in noisy environments.

type?: "server_vad" | "semantic_vad"

Type of turn detection.