Text to speech error, conflicting with the speech to text button

Question

I am trying to use iOS speech to text api and text to speech api together. Basically a user will speak and what they say will be transcribed in a textview. Then the user will press a button which will provide text to speech from the transcribed text in the textview. My error is that when the user presses the speech-to-text button, the text to speech button stops working. However if I don't press the speech to text button at all and input some text in the textview via keyboard then text to speech button works. I am guess it is has issue with the speech to text button. I am not getting any errors on my code and i am confused as to what is going on.

import UIKit
import Speech
import AVFoundation

class SpeechRecognitionViewController: UIViewController, SFSpeechRecognizerDelegate, UIPickerViewDataSource, UIPickerViewDelegate {

    private var speechRecognizer: SFSpeechRecognizer!
    private var recognitionRequest: SFSpeechAudioBufferRecognitionRequest!
    private var recognitionTask: SFSpeechRecognitionTask!
    private let audioEngine = AVAudioEngine()
    private var locales: [Locale]!
    private let defaultLocale = Locale(identifier: "en-US")

    @IBOutlet weak var recordBtn: UIButton!

    @IBOutlet weak var speaker: UIButton!
    @IBOutlet weak var textView: UITextField!
    //@IBOutlet weak var textView: UITextView!
    //@IBOutlet private weak var recordBtn : UIButton!
    //@IBOutlet private weak var picker: UIPickerView!
    @IBOutlet weak var picker: UIPickerView!


    override func viewDidLoad() {
        super.viewDidLoad()

        recordBtn.isEnabled = false

        locales = SFSpeechRecognizer.supportedLocales().map({$0})

        let index = NSArray(array: locales).index(of: defaultLocale)
        picker.selectRow(index, inComponent: 0, animated: false)

        prepareRecognizer(locale: defaultLocale)
    }

    override func viewDidAppear(_ animated: Bool) {
        super.viewDidAppear(animated)

        SFSpeechRecognizer.requestAuthorization { authStatus in
            /*
             The callback may not be called on the main thread. Add an
             operation to the main queue to update the record button's state.
             */
            OperationQueue.main.addOperation {
                switch authStatus {
                case .authorized:
                    self.recordBtn.isEnabled = true

                case .denied:
                    self.recordBtn.isEnabled = false
                    self.recordBtn.setTitle("User denied access to speech recognition", for: .disabled)

                case .restricted:
                    self.recordBtn.isEnabled = false
                    self.recordBtn.setTitle("Speech recognition restricted on this device", for: .disabled)

                case .notDetermined:
                    self.recordBtn.isEnabled = false
                    self.recordBtn.setTitle("Speech recognition not yet authorized", for: .disabled)
                }
            }
        }
    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
    }

    private func prepareRecognizer(locale: Locale) {
        speechRecognizer = SFSpeechRecognizer(locale: locale)!
        speechRecognizer.delegate = self
    }

    private func startRecording() throws {

        // Cancel the previous task if it's running.
        if let recognitionTask = recognitionTask {
            recognitionTask.cancel()
            self.recognitionTask = nil
        }

        let audioSession = AVAudioSession.sharedInstance()
        try audioSession.setCategory(AVAudioSessionCategoryRecord)
        try audioSession.setMode(AVAudioSessionModeMeasurement)
        try audioSession.setActive(true, with: .notifyOthersOnDeactivation)

        recognitionRequest = SFSpeechAudioBufferRecognitionRequest()

        guard let inputNode = audioEngine.inputNode else { fatalError("Audio engine has no input node") }
        guard let recognitionRequest = recognitionRequest else { fatalError("Unable to created a SFSpeechAudioBufferRecognitionRequest object") }

        // Configure request so that results are returned before audio recording is finished
        recognitionRequest.shouldReportPartialResults = true

        // A recognition task represents a speech recognition session.
        // We keep a reference to the task so that it can be cancelled.
        recognitionTask = speechRecognizer.recognitionTask(with: recognitionRequest) { result, error in
            var isFinal = false

            if let result = result {
                self.textView.text = result.bestTranscription.formattedString
                isFinal = result.isFinal
            }

            if error != nil || isFinal {
                self.audioEngine.stop()
                inputNode.removeTap(onBus: 0)

                self.recognitionRequest = nil
                self.recognitionTask = nil

                self.recordBtn.isEnabled = true
                self.recordBtn.setTitle("Start Recording", for: [])
            }
        }

        let recordingFormat = inputNode.outputFormat(forBus: 0)
        inputNode.installTap(onBus: 0, bufferSize: 1024, format: recordingFormat) { (buffer: AVAudioPCMBuffer, when: AVAudioTime) in
            self.recognitionRequest?.append(buffer)
        }

        audioEngine.prepare()

        try audioEngine.start()

        textView.text = "(listening...)"
    }

    // =========================================================================
    // MARK: - UIPickerViewDataSource

    func numberOfComponents(in pickerView: UIPickerView) -> Int {
        return 1
    }

    func pickerView(_ pickerView: UIPickerView, numberOfRowsInComponent component: Int) -> Int {
        return locales.count
    }

    // =========================================================================
    // MARK: - UIPickerViewDelegate

    func pickerView(_ pickerView: UIPickerView, titleForRow row: Int, forComponent component: Int) -> String? {
        return locales[row].identifier
    }

    func pickerView(_ pickerView: UIPickerView, didSelectRow row: Int, inComponent component: Int) {
        let locale = locales[row]
        prepareRecognizer(locale: locale)
    }

    // =========================================================================
    // MARK: - SFSpeechRecognizerDelegate

    public func speechRecognizer(_ speechRecognizer: SFSpeechRecognizer, availabilityDidChange available: Bool) {
        if available {
            recordBtn.isEnabled = true
            recordBtn.setTitle("Start Recording", for: [])
        } else {
            recordBtn.isEnabled = false
            recordBtn.setTitle("Recognition not available", for: .disabled)
        }
    }

    // =========================================================================
    // MARK: - Actions


    @IBAction func recordbuttontapped(_ sender: Any) {

        if audioEngine.isRunning {
            audioEngine.stop()
            recognitionRequest?.endAudio()
            recordBtn.isEnabled = false
            recordBtn.setTitle("Stopping", for: .disabled)
        } else {
            try! startRecording()
            recordBtn.setTitle("Stop recording", for: [])
        }
    }

    @IBAction func speaktome(_ sender: Any) {

        let something = textView.text!
        let utterance = AVSpeechUtterance(string: something)
        utterance.voice = AVSpeechSynthesisVoice(language: "en-US" )

        let synthesizer = AVSpeechSynthesizer()

        synthesizer.speak(utterance)
    }
}

Answer 1

Change the try audioSession.setCategory(AVAudioSessionCategoryRecord) to try audioSession.setCategory(AVAudioSessionCategoryPlayAndRecord) it should work as intended. During speech to text you are changing the audio session to record mode and it is not getting changed to play mode during TTS. The other alternative is to set the audio session to AVAudioSessionCategoryPlayback during the TTS.

Answer 2

use another thread to get voice in this condition when you press speech-to-text button your program focus on getting voice from user and its a infinite condition or continually your program getting voice not any halt condition,use another thread to get the user voice on speech-to-text button and terminate after getting voice