0 and 100, where higher means the model is more certain. There are two families:
- Frame-level probability scores — well-calibrated probabilities sampled on a regular time axis, describing what is happening in the audio at each instant.
- Confidence scores — how certain the model is about a speaker assignment, per turn.
Which scores are available
All of these work the same way on diarize and identify.
Frame-level probability scores
The three probability scores answer three different questions about the same moment in time:speechProbability— is anyone speaking?crosstalkProbability— is more than one person speaking?speakerProbability— is this particular speaker speaking?
false. Each returns an object with a score and a resolution:
Example output
score— forspeechProbabilityandcrosstalkProbability, an array of values between0and100. ForspeakerProbability, an object keyed by speaker label, each holding such an array.resolution— seconds per sample. Fixed at0.02(20ms).
i refers to the same 20ms window in every score. To convert an index to a timestamp, multiply by the resolution: sample i starts at i * resolution seconds.
Example request
output_scores.py
What to use the scores for
The scores exist so the decision can belong to your product logic rather than to the model.- Building high-quality voiceprints — keep only segments above a
speakerProbabilityorturnLevelConfidencethreshold, trading recall for precision. - Routing to human review — flag segments below a threshold instead of reviewing a whole transcript.
- Monitoring quality over time — track probability distributions per audio source to catch drift before it reaches your users.
- Resolving overlap for speech-to-text — most STT engines transcribe one speaker at a time. Use
speakerProbabilityto decide which speaker is most likely being transcribed, or let exclusive diarization do it for you. - Extracting clean training data — raise
crosstalkSensitivityto over-detect overlap (or filter oncrosstalkProbability) to remove every contaminated section.
Confidence scores
Confidence scores measure how certain the model is about a speaker assignment, rather than about acoustic activity. There are two kinds.Turn-level confidence
Add"turnLevelConfidence": true to your request. Each diarization segment gains a confidence object, keyed by speaker, giving the confidence of that speaker assignment:
Identification confidence
Identification confidence is specific to speaker identification and shows how well each voiceprint matches each speaker. It is included automatically when using the identify endpoint — no parameter required.Identification confidence scores are different from diarization confidence scores. They measure how well a voiceprint matches a speaker, not how certain the diarization model is about the speaker assignment.