Description of the bug:
Gemini Live API: Input transcription drops beginning of long pause-heavy user turns
Hi team,
We're evaluating the Live API (gemini-3.1-flash-live-preview) for a real-time voice application and have observed what appears to be truncation of input transcription during long user turns containing natural pauses.
Environment
Model: gemini-3.1-flash-live-preview
Server-side activity detection enabled
Input and output audio transcription enabled
Default activity detection settings, except:
prefix_padding_ms = 300
Observed behaviour
When a user speaks for an extended period with occasional natural pauses (typically 1–3 seconds), the input transcription received by the application sometimes contains only the latter portion of the user's speech. The beginning of the utterance appears to be missing, with the transcription starting partway through the response.
In our testing:
Total user speech duration was approximately 90–100 seconds.
Our client-side audio telemetry indicates approximately 90–100 seconds of speech was transmitted successfully.
Speech included several natural pauses between sentences.
The final input transcription contained only the latter part of the response rather than the full utterance.
Session logs showed an interrupted/resumed speech event during the turn.
The transcript begins mid-sentence, suggesting earlier content may not have been retained.
Questions
Is this expected behaviour when server-side activity detection determines that a turn has ended and subsequently starts a new activity?
Are there any limits on input transcription duration, buffer size, or retained audio that could result in earlier portions of speech being omitted?
For users who may speak for extended periods with occasional 1–3 second pauses, what activity detection settings do you recommend (e.g. silence duration, start/end sensitivity)?
Is there a supported approach for ensuring transcription continuity across pauses within a single logical user turn?
For long-form spoken responses, would you recommend manual activity detection rather than automatic turn detection?
We'd appreciate any recommended configuration, implementation pattern, or best practice for handling long-form user speech while preserving complete transcription fidelity.
Happy to provide session IDs, timestamps, logs, and a minimal reproduction example if that would help with investigation.
Thanks in advance for any guidance.
Actual vs expected behavior:
No response
Any other information you'd like to share?
No response
Description of the bug:
Gemini Live API: Input transcription drops beginning of long pause-heavy user turns
Hi team,
We're evaluating the Live API (gemini-3.1-flash-live-preview) for a real-time voice application and have observed what appears to be truncation of input transcription during long user turns containing natural pauses.
Environment
Model: gemini-3.1-flash-live-preview
Server-side activity detection enabled
Input and output audio transcription enabled
Default activity detection settings, except:
prefix_padding_ms = 300
Observed behaviour
When a user speaks for an extended period with occasional natural pauses (typically 1–3 seconds), the input transcription received by the application sometimes contains only the latter portion of the user's speech. The beginning of the utterance appears to be missing, with the transcription starting partway through the response.
In our testing:
Total user speech duration was approximately 90–100 seconds.
Our client-side audio telemetry indicates approximately 90–100 seconds of speech was transmitted successfully.
Speech included several natural pauses between sentences.
The final input transcription contained only the latter part of the response rather than the full utterance.
Session logs showed an interrupted/resumed speech event during the turn.
The transcript begins mid-sentence, suggesting earlier content may not have been retained.
Questions
Is this expected behaviour when server-side activity detection determines that a turn has ended and subsequently starts a new activity?
Are there any limits on input transcription duration, buffer size, or retained audio that could result in earlier portions of speech being omitted?
For users who may speak for extended periods with occasional 1–3 second pauses, what activity detection settings do you recommend (e.g. silence duration, start/end sensitivity)?
Is there a supported approach for ensuring transcription continuity across pauses within a single logical user turn?
For long-form spoken responses, would you recommend manual activity detection rather than automatic turn detection?
We'd appreciate any recommended configuration, implementation pattern, or best practice for handling long-form user speech while preserving complete transcription fidelity.
Happy to provide session IDs, timestamps, logs, and a minimal reproduction example if that would help with investigation.
Thanks in advance for any guidance.
Actual vs expected behavior:
No response
Any other information you'd like to share?
No response