How to detect when SAPI TTS engine is busy

Question

The SAPI engine can only render TTS from one application at a time (I have run a test with two instances of the Windows SDK TTSApplication sample to verify this). I am writing an application in which I need to detect whether the TTS engine is currently speaking (i.e. under control of a separate application, not mine).

Does anyone know please how can I programmatically (in C++) detect the SAPI TTS engine busy/ready state? I have tried using ISpVoice::GetStatus() but that only seems to work for any TTS activity in my own application.

Thanks.

Answer 1

For example in SAPI4, IVTxtAttributes::IsSpeaking retrieve such status (if engine is currently playing samples to some audio device).

Anyway IMO general SAPI engine is not limited to one application. I believe that this behaviour is 'your engine' specific.