使用iPhone扬声器AVSpeechSynthesizer

Question

我使用下面的代码添加文本到语音功能在我的iOS应用：

try! AVAudioSession.sharedInstance().setCategory(AVAudioSessionCategoryPlayAndRecord, withOptions: AVAudioSessionCategoryOptions.DefaultToSpeaker) 
try! AVAudioSession.sharedInstance().setActive(true) 
try! AVAudioSession.sharedInstance().overrideOutputAudioPort(AVAudioSessionPortOverride.Speaker) 

let speech : String = "You have the following items in your To-do list: " 
let speechUtterance : AVSpeechUtterance = AVSpeechUtterance(string: speech) 
AVSpeechSynthesizer().speakUtterance(speechUtterance) 

的代码工作完全正常，但声音是从手机的麦克风来了。我想使用扬声器而不是麦克风。我如何实现这一目标？

Answer 1

我使用SFSpeechRecognizer进行语音识别，然后为了演讲者发言，您必须执行以下操作。

let audioSession = AVAudioSession.sharedInstance() 
    do { 

    try! audioSession.setCategory(AVAudioSessionCategoryPlayAndRecord) 
    try audioSession.setMode(AVAudioSessionModeSpokenAudio) 
    try audioSession.setActive(true, with: .notifyOthersOnDeactivation) 

        let currentRoute = AVAudioSession.sharedInstance().currentRoute 
         for description in currentRoute.outputs { 
          if description.portType == AVAudioSessionPortHeadphones { 
           try audioSession.overrideOutputAudioPort(AVAudioSessionPortOverride.none) 
           print("headphone plugged in") 
          } else { 
           print("headphone pulled out") 
           try audioSession.overrideOutputAudioPort(AVAudioSessionPortOverride.speaker) 
          } 
        } 

} catch { 
     print("audioSession properties weren't set because of an error.") 
}