NSString* msg = @"Hello, how are you?";
AVSpeechUtterance *utterance = [AVSpeechUtterance
speechUtteranceWithString: msg];
utterance.rate = AVSpeechUtteranceMaximumSpeechRate;
utterance.pitchMultiplier = 1.0f;
utterance.voice =[AVSpeechSynthesisVoice voiceWithLanguage:@"en-US"];
utterance.volume = 1.0f;
utterance.postUtteranceDelay = 5;
AVSpeechSynthesizer *synth = [[AVSpeechSynthesizer alloc] init];
synth.delegate = self;
[self log:@"Start Speech"];
[synth speakUtterance:utterance];
Is it a bug on speech framework? It works on iOS 10, but now it doesn't work on iOS 11. I heard the voice of speech, but it never call didFinishSpeechUtterance.