如何在swift中增加AVSpeechUtterance音量

Question

当我在模拟器中运行时，我使用我的项目AVSpeechUtterance进行文本到语音转换的所有工作都很好，但是当我在我的设备中运行时，语音音量非常慢，这里是我的代码……

        let utterance = AVSpeechUtterance(string: "Good night all")

    if UserDefaults.standard.string(forKey: "LNG") == "Eng"
    {
        utterance.voice = AVSpeechSynthesisVoice(language: "en-US")
    }
    else
    {
        utterance.voice = AVSpeechSynthesisVoice(language: "de-DE")
    }

    utterance.rate = AVSpeechUtteranceDefaultSpeechRate
    utterance.volume = 1
    let synth = AVSpeechSynthesizer()
    synth.speak(utterance)

Answer 1

对于不同的设备，默认值可能不同。你查过了吗？

您可以通过转到Settings>Accessibility>Spoken Content来查看设备的设置

让用户有机会调整这个速率，因为理想的速率对于很多人来说可能是不同的

import SwiftUI
import Speech
class SpeechManager:ObservableObject{
    //The default value is likely different for the devices
    //You can also look up what the device has set by going to Settings>Accessibility>Spoken Content
    var defaultRate = AVSpeechUtteranceDefaultSpeechRate
    //Stuff like this is the intended use of UserDefaults
    var userSpeechRate: Float{
        get{
            UserDefaults.standard.value(forKey: "userSpeechRate") as? Float ?? AVSpeechUtteranceDefaultSpeechRate
        }
        set{
            UserDefaults.standard.set(newValue, forKey: "userSpeechRate")
            objectWillChange.send()
        }
    }
    //You can save the volume too.
    //If your device doesn't respond to this change it is likely a hardware issue or a specific setting on the device.
    //Something like the device volume and Silent mode button being off
    var userSpeechVolume: Float{
        get{
            UserDefaults.standard.value(forKey: "userSpeechVolume") as? Float ?? 1
        }
        set{
            UserDefaults.standard.set(newValue, forKey: "userSpeechVolume")
            objectWillChange.send()
        }
    }
    //This is mostly your code with the exception of setting a custom rate
    func sayGoodNight(){
        let utterance = AVSpeechUtterance(string: "Good night all")
        
        if UserDefaults.standard.string(forKey: "LNG") == "Eng"
        {
            utterance.voice = AVSpeechSynthesisVoice(language: "en-US")
        }
        else
        {
            utterance.voice = AVSpeechSynthesisVoice(language: "de-DE")
        }
        //Change this to use the
        utterance.rate = userSpeechRate
        utterance.volume = userSpeechVolume
        let synth = AVSpeechSynthesizer()
        synth.speak(utterance)
    }
}
struct SpeechView: View {
    @StateObject var vm: SpeechManager = SpeechManager()
    var body: some View {
        VStack{
            Text("default rate \(vm.defaultRate)")
            Text("user rate \(vm.userSpeechRate)")
            Slider(value: $vm.userSpeechRate, in: 0...1, label: {Text("speech rate")})
            Slider(value: $vm.userSpeechVolume, in: 0...1, label: {Text("speech volume")})
            Button("say goodnight", action: {
                vm.sayGoodNight()
            })
        }
    }
}

struct SpeechView_Previews: PreviewProvider {
    static var previews: some View {
        SpeechView()
    }
}