gemini-3.8-live emits no VoiceActivity (documented replacement for deprecated speechState)

[r09528039]

The Live API reference marks speechState as deprecated: "Use VoiceActivity instead". gemini-3.1-flash-live-preview emits voiceActivity (top-level, ACTIVITY_START / ACTIVITY_END with audioOffset) on both v1alpha and v1beta. gemini-3.8-live and gemini-3.8-live-extended-thinking emit nothing during user speech.

VoiceActivity is referenced by the deprecation note but not defined on the reference page nor listed in the BidiGenerateContentServerMessage union.

Is the absence of any server-side voice-activity signal on 3.8 intended?

[Venkaiahbabuneelam]

Hi @r09528039,

Thanks for the clear explanation! You are right that gemini-3.8-live models do not send VoiceActivity signals at this time.

We are escalating this issue internally to investigate further. If you need voice activity detection right now, please use gemini-3.1-flash-live-preview as a workaround.

We’ll keep you updated on progress. Thanks!