Caller Comfort Audio
Keep callers company with configured audio while a slow tool call runs — for ordinary HTTP tools and MCP tools alike.
Configuration
Add toolCallComfortAudio to VoiceElements_Instructions
and point it at a mediaCatalog item:
{
"mediaCatalog": [
{ "mediaReference": "ApiWaitComfort" }
],
"toolCallComfortAudio": {
"mediaReference": "ApiWaitComfort",
"startDelayMilliseconds": 2000,
"maximumSeconds": 120
}
}| Field | Default | Description |
|---|---|---|
| mediaReference | — | The mediaCatalog item to play. A missing/null toolCallComfortAudio object or a blank mediaReference disables the feature. |
| startDelayMilliseconds | 2000 | How long the caller must stay quiet before comfort audio starts. Constrained to 2000–5000. |
| maximumSeconds | 120 | Upper bound on comfort playback. Constrained to 1–3600. |
Omitting toolCallComfortAudio keeps ordinary AI/tool routing with no comfort playback.
Behavior
Comfort audio is driven by the tool call's lifecycle and the playback state — not by matching a phrase in the transcript.
The tool request starts immediately
The external HTTP or MCP request begins right away. Comfort audio never delays it.
Comfort waits for genuine silence
It starts only after any preceding AI audio has finished and the caller has stayed quiet through startDelayMilliseconds.
The AI keeps listening
While comfort plays, the caller hears the comfort source, but the AI continues to hear the caller.
Speech interrupts cleanly
Caller speech or a new AI response restores full routing before any AI audio is played. If the same tool is still pending after genuine silence, comfort may resume.
The result always gets through
Tool completion, failure, timeout, or cancellation restores full routing before the AI speaks the result.
Failures are harmless
Missing media or a playback/routing failure never alters the tool request or its result.
vns_allow_mcp_calls as described in the MCP Integration guide.
This release logs comfort playback operationally; there is no separate comfort-audio field in CallEnd.
Instruction Guidance
Add something like this to your instructions so the model sets expectations and leaves the waiting audio to VNS:
Before a potentially slow tool call, briefly tell the caller what you are doing, for example, "One moment while I confirm that appointment." Then call the tool. Do not generate filler sounds or pretend that the operation has completed. Voice Nexus controls configured comfort audio while the tool is pending.Ready to Automate Your Phone Lines?
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