On my end, Xcode 26.1.1 can synthesize for the first time then never, will have to restart app. With Xcode 26.2, synthesis outright stopped working. Tried older simulators down to 18.2, no luck. I am on macOS 26.1 The only thing that worked is through writing to a file instead of asking it to speak directly. That will work every time Speaking directly in a macOS app also doesn't work

After upgrading to macOS 26.2, speaking programmatically in a macOS app still doesn't work, it doesn't work either on iOS simulators. If you synthesize to a file (.caf) and play it back then it will work every time on iOS 26.2 simulator (didn't test on other versions but should work)

turns out, it could be a behavior change before: AVSpeechSynthesizer().speak(AVSpeechUtterance(string: "hello word")) probably after some behaviour change which is also a good change, the playback will also tie with the life span of the AVSpeechSynthesizer instance that starts it. so you will need to find somewhere to hold the instance, otherwise the instance will go out of scope after: @state var synthesizer: AVSpeechSynthesizer? // ... synthesizer = AVSpeechSynthesizer() synthesizer?.speak(AVSpeechUtterance(string: "hello word"))

existing tutorials and articles will need to be updated or everyone might land on this page (or llm might take a clue of this or directly point to this)