Options of the Call.say method.
Use progressive playback or not. If true, the generated speech will be delivered in chunks which reduces delay before a method call and playback. It's false by default.
Optional parameters for TTS. SSML markup can be used to control aspects of speech such as pronunciation, volume, pitch, rate, etc. Note that if you specify at least one of these parameters, Voxengine automatically adds the <speak>...</speak> tags to either end of a passed string. If you want to use other SSML tags, specify the <speak>...</speak> tags manually.