Platform SDK: Agent

IAgentAudioOutputProperties::GetEnabled

HRESULT GetEnabled(
long * pbEnabled  // address of variable for audio output Enabled setting 
);                      

Retrieves a value indicating whether character speech output is enabled.

pbEnabled
Address of a variable that receives True if the speech output is currently enabled and False if disabled.

Because this setting affects spoken output (TTS and sound file) for all characters, only the user can change this property in the Microsoft Agent property sheet.