kSpeechPreflightThenPause

Declaration

let kSpeechPreflightThenPause: CFString

Discussion

The kSpeechPreflightThenPause key is used to minimize the latency experienced when the speech synthesizer is attempting to speak. To achieve this, specify the kSpeechPreflightThenPause key, with the value kCFBooleanTrue, in the options dictionary. This causes the speech synthesizer to process the input text as necessary to the point where it is ready to begin producing speech output. At this point, the synthesizer enters a paused state and returns to the caller. When the application is ready to produce speech, it should call ContinueSpeech(_:) to begin speaking.

If you do not specify the kSpeechPreflightThenPause key (or you specify it with the value kCFBooleanFalse), SpeakCFString(_:_:_:) starts speaking the input text after processing it.