| AlwaysOnHotwordDetector | A class that lets a VoiceInteractionService implementation interact with always-on keyphrase detection APIs. | 
| AlwaysOnHotwordDetector.Callback | Callbacks for always-on hotword detection. | 
| AlwaysOnHotwordDetector.EventPayload | Additional payload for onDetected(AlwaysOnHotwordDetector.EventPayload). | 
| VoiceInteractionService | Top-level service of the current global voice interactor, which is providing
 support for hotwording, the back-end of a VoiceInteractor, etc. | 
| VoiceInteractionSession | An active voice interaction session, providing a facility for the implementation to interact with the user in the voice interaction layer. | 
| VoiceInteractionSession.AbortVoiceRequest | A request to report that the current user interaction can not be completed with voice, as per VoiceInteractor.AbortVoiceRequest. | 
| VoiceInteractionSession.CommandRequest | A generic vendor-specific request, as per VoiceInteractor.CommandRequest. | 
| VoiceInteractionSession.CompleteVoiceRequest | A request to simply inform the user that the voice operation has completed, as per VoiceInteractor.CompleteVoiceRequest. | 
| VoiceInteractionSession.ConfirmationRequest | A request for confirmation from the user of an operation, as per VoiceInteractor.ConfirmationRequest. | 
| VoiceInteractionSession.Insets | Information about where interesting parts of the input method UI appear. | 
| VoiceInteractionSession.PickOptionRequest | A request for the user to pick from a set of option, as per VoiceInteractor.PickOptionRequest. | 
| VoiceInteractionSession.Request | Base class representing a request from a voice-driver app to perform a particular voice operation with the user. | 
| VoiceInteractionSessionService | An active voice interaction session, initiated by a VoiceInteractionService. |