How does endpointing work?
The IETF’s Media Resource Control Protocol, RFC 6787, defines endpointing as automatically detecting the beginning and end of speech in an audio stream, and calls it critical for both speech recognition and recording.
The classic method is a silence timeout. A voice activity detector marks speech, and once the speaker has been quiet for a set time, the system treats the utterance as complete. The W3C’s VoiceXML 2.0 standard calls this the complete timeout and says reasonable values are typically 0.3 to 1.0 seconds: a long one makes the system slow to respond, and a short one may break an utterance up. A longer incomplete timeout applies when the words so far aren’t a complete answer, so people can pause mid-sentence, for example to breathe.
Newer systems judge the words as well as the silence. OpenAI’s semantic VAD, for example, scores how likely it is that the speaker has finished, so trailing off earns a longer wait than a definite statement.
Example: a caller says “My invoice shows the wrong…”, pauses to find the amount, then carries on. A 500-millisecond silence timeout may answer the half sentence, while a word-aware endpointer is more likely to wait.
Why does endpointing matter for a voice agent?
It sits behind two familiar complaints about voice agents. An eager endpointer cuts off people who pause to think, read out a number or search for a word. A patient one leaves a gap before every reply, which makes the agent seem slow.
The right balance depends on the conversation. Support callers describing a problem pause more than people answering yes or no. In a full-duplex system that keeps listening while it speaks, the agent also has to tell a new turn from a brief “mm-hmm” or a cough.
How does Kawl Now handle endpointing?
Kawl Now has no endpointing settings: there’s no silence timeout or eagerness control in the dashboard, the REST API or the MCP server. Calls run on OpenAI’s GPT-Live, which manages turn-taking itself, including when to reply.
So timing isn’t something you can tune in Kawl Now today. What you can do is test it: spell out an email address slowly, stop mid-sentence to think and answer with a single word, then read each transcript to see whether the agent waited.
Common questions
What is a good endpointing timeout?
There’s no single right value. The W3C’s VoiceXML standard suggests 0.3 to 1.0 seconds of silence after a complete answer, with a longer wait when the answer is incomplete. Shorter suits quick yes-or-no exchanges, and longer suits callers describing a problem.
Why does a voice agent interrupt me?
Usually because its endpointing treats a pause as the end of your turn, or because noise or its own echo is detected as speech. Longer silence timeouts, end-of-turn models that read the words, echo cancellation and noise suppression all reduce it.