Start Recording Function

StartRecordingTranscription.swift

//Thanks to https://developer.apple.com/documentation/speech/recognizing_speech_in_live_audio
func startRecording() throws {
        
        // Cancel the previous task if it's running.
        recognitionTask?.cancel()
        self.recognitionTask = nil
        
        // Configure the audio session for the app.
        let audioSession = AVAudioSession.sharedInstance()
        try audioSession.setCategory(.record, mode: .measurement, options: .duckOthers)
        try audioSession.setActive(true, options: .notifyOthersOnDeactivation)
        let inputNode = audioEngine.inputNode

        // Create and configure the speech recognition request.
        recognitionRequest = SFSpeechAudioBufferRecognitionRequest()
        guard let recognitionRequest = recognitionRequest else { fatalError("Unable to create a SFSpeechAudioBufferRecognitionRequest object") }
        recognitionRequest.shouldReportPartialResults = true
        
        // Keep speech recognition data on device
        if #available(iOS 13, *) {
            recognitionRequest.requiresOnDeviceRecognition = false
        }
        
        // Create a recognition task for the speech recognition session.
        // Keep a reference to the task so that it can be canceled.
        recognitionTask = speechRecognizer.recognitionTask(with: recognitionRequest) { result, error in
            var isFinal = false
            
            if let result = result {
                // ***We will update State here!***
                // ??? = result.bestTranscription.formattedString
                isFinal = result.isFinal
                print("Text \(result.bestTranscription.formattedString)")
            }
            
            if error != nil || isFinal {
                // Stop recognizing speech if there is a problem.
                self.audioEngine.stop()
                inputNode.removeTap(onBus: 0)

                self.recognitionRequest = nil
                self.recognitionTask = nil
            }
        }

        // Configure the microphone input.
        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()
    }