Type	Topic	Plugin	Version	macOS	Windows	Linux	iOS	Targets
class	Speech	MBS AVFoundation Plugin	24.1	✅ Yes	❌ No	❌ No	✅ Yes	All

An object that produces synthesized speech from text utterances and enables monitoring or controlling of ongoing speech.

To speak some text, create an AVSpeechUtteranceMBS instance that contains the text and pass it to speakUtterance on a speech synthesizer instance. You can optionally also retrieve an AVSpeechSynthesisVoiceMBS and set it on the utterance’s voice property to have the speech synthesizer use that voice when speaking the utterance’s text.

The speech synthesizer maintains a queue of utterances that it speaks. If the synthesizer isn’t speaking, calling speakUtterance: begins speaking that utterance either immediately or after pausing for its preUtteranceDelay, if necessary. If the synthesizer is speaking, the synthesizer adds utterances to a queue and speaks them in the order it receives them.
After speech begins, you can use the synthesizer object to pause or stop speech. After pausing, you can resume the speech from its paused point or stop the speech entirely and remove all remaining utterances in the queue.
You can monitor the speech synthesizer by examining its speaking and paused properties, or by adding events.

An AVSpeechSynthesizerMBS also controls the route where the speech plays. For more information, see Directing speech output.

The system doesn’t automatically retain the speech synthesizer, so you need to manually retain it until speech concludes.