A basic text-to-speech API intended to be used for audio accessibility.

Implementations of this API should audibly play back text to assist users in
non-visual navigation of the application.

Note that these functions do not have to be thread-safe. They must only be
called from a single application thread.

## Functions

### SbSpeechSynthesisCancel

Cancels all speaking and queued speech synthesis audio. Must return immediately.

#### Declaration

    void SbSpeechSynthesisCancel()

### SbSpeechSynthesisIsSupported

Returns whether the platform supports speech synthesis

#### Declaration

    bool SbSpeechSynthesisIsSupported()

### SbSpeechSynthesisSpeak

Enqueues `text`, a UTF-8 string, to be spoken. Returns immediately.

Spoken language for the text should be the same as the locale returned by
SbSystemGetLocaleId().

If audio from previous SbSpeechSynthesisSpeak() invocations is still processing,
the current speaking should continue and this new text should be queued to play
when the previous utterances are complete.

#### Declaration

    void SbSpeechSynthesisSpeak(const char *text)