AVSpeechUtterance无声语音

Question

我正在使用AVSpeechUtterance来讲给定的文本。我正在使用下面的代码，并在'iPhone林格模式‘工作良好，但当我将iPhone改为’沉默模式‘时，声音变得静音。当它是“沉默模式”时，我无法听到它的声音。我该怎么做才能听到“沉默模式”中的声音呢？

AVSpeechUtterance *utterance = [[AVSpeechUtterance alloc] initWithString:@"Hello World"];
utterance.voice = [AVSpeechSynthesisVoice voiceWithLanguage:@"en-US"];
[utterance setRate:AVSpeechUtteranceMinimumSpeechRate];
[utterance setVolume:1];
[self.speechSynthesizer speakUtterance:utterance];

Answer 1

在代码之前添加以下代码。您也可以在appDelegate中编写相同的代码。

NSError *setCategoryErr = nil;
NSError *activationErr  = nil;
[[AVAudioSession sharedInstance] setCategory: AVAudioSessionCategoryPlayback error:&setCategoryErr];
[[AVAudioSession sharedInstance] setActive:YES error:&activationErr];

Answer 2

Swift 3.0答案

do {
    try AVAudioSession.sharedInstance().setCategory(AVAudioSessionCategoryPlayback)
}
catch let error as NSError {
    print("Error: Could not set audio category: \(error), \(error.userInfo)")
}

do {
    try AVAudioSession.sharedInstance().setActive(true)
}
catch let error as NSError {
    print("Error: Could not setActive to true: \(error), \(error.userInfo)")
}

Answer 3

我也遇到了类似的问题，我通过添加AVAudio session方法修复了这个问题。Swift 5.0

    // this  AVAudioSession method is for speak text when device is in silent mode
    do {
        try AVAudioSession.sharedInstance().setCategory(.playback,mode: .default)

    } catch let error {
        print("This error message from SpeechSynthesizer \(error.localizedDescription)")
    }
    
    let speechSynthesizer = AVSpeechSynthesizer()
    let speechUtterance: AVSpeechUtterance = AVSpeechUtterance(string: text)
    
    speechUtterance.rate = AVSpeechUtteranceMaximumSpeechRate / 2.3
    speechUtterance.voice = AVSpeechSynthesisVoice(language: "en-US")
    speechSynthesizer.speak(speechUtterance)
    
}