Optionalchannel?: ChannelOptionalchannelTrue if channel was filled in by channelAttribution.resolveUnknownChannelsMethod
rather than by the per-word VAD. Only set on words whose per-word VAD
attribution was "unknown" and whose resolution method produced a
confident channel. Useful for debugging or rendering an indicator that a
word's channel came from context, not direct VAD evidence.
Optionalspeaker?: string
Physical input channel attributed by client-side VAD during this word's time window. Populated only when the transcriber is configured with
channels. Independent fromspeaker.