OptionalaudioAudio effects applied to ONLY this turn's synthesized audio, overriding the simulator's default effects for the turn. (PRD §4.2 L293.)
OptionalvoiceApply a voice style (e.g. "angry") to ONLY this turn's TTS. Reverts to
the simulator's default voice on subsequent turns. (PRD §4.2 L290.)
Per-step voice overrides for user (PRD §4.2).