使用带有AVSpeechSynthesizer的iPhone扬声器

Question

我使用以下代码在iOS应用中为语音功能添加文字：

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)

代码工作得非常好，但声音来自手机的麦克风。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，之后为了对说话者发表话语，你必须遵循。

  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.")
}