# Text-to-Speech events

> Learn about text-to-speech event callbacks.

The SDK can sometimes raise the following `ITextToSpeech` text-to-speech (TTS) events.

> **Note:**
>
> You can bind to these events by using `ILoginSession::TTS()`.

* `EventPlaybackStarted` - Raised when a TTS message has finished preparing for playback and is starting to play.

  * `Message` - The `ITTSMessage` that corresponds to this speech.
  * `MessageDuration` - The duration of the synthesized voice clip in seconds.
  * `NumConsumers` - The number of active sessions (for remote playback destinations) or local players (for local playback destinations), or both, that the TTS message was injected into.

* `EventPlaybackCompleted` - Raised when a TTS message has finished playback.

  * `Message` - The `ITTSMessage` that corresponds to this speech.
  * `NumConsumers` - The number of active sessions (for remote playback destinations) or local players (for local playback destinations), or both, that the TTS message was injected into.

* `EventPlaybackFailed` - Raised when playback of a TTS message has failed.

  * `Message` - The `ITTSMessage` that corresponds to this speech.
  * `Status` - The error code of the failure.