Pfthb

I am using the Siri speech kit and while using it and clicking of the button some times it will be terminated and shows the error message as title.
I am using the single button and when first clicks it here to our voice and and again click on the button stop listening that is the main functionality.

`func startRecording() 
 messageField.text = ""
 if recognitionTask != nil 
 recognitionTask?.cancel()
 recognitionTask = nil
 
 let audioSession = AVAudioSession.sharedInstance()
 do 
 try audioSession.setCategory(AVAudioSessionCategoryPlayAndRecord,mode: AVAudioSessionModeDefault, options: .defaultToSpeaker)
 try audioSession.setMode(AVAudioSessionModeMeasurement)
 try audioSession.setActive(true, with: .notifyOthersOnDeactivation)
 catch 
 print("audioSession properties weren't set because of an error.")
 
 recognitionRequest = SFSpeechAudioBufferRecognitionRequest()
 let inputNode = audioEngine.inputNode
 guard let recognitionRequest = recognitionRequest else 
 fatalError("Unable to create an SFSpeechAudioBufferRecognitionRequest object")
 
 recognitionRequest.shouldReportPartialResults = true
 recognitionTask = speechRecognizer.recognitionTask(with: recognitionRequest, resultHandler: isFinal 
 self.audioEngine.stop()
 self.audioEngine.inputNode.removeTap(onBus: 0)

 self.recognitionRequest = nil
 self.recognitionTask = nil
 // self.microphoneButton.isEnabled = true
 
 )
 let recordingFormat = inputNode.outputFormat(forBus: 0)
 inputNode.installTap(onBus: 0, bufferSize: 1024, format: recordingFormat) (buffer, when) in
 self.recognitionRequest?.append(buffer)
 
 audioEngine.prepare()

 do 
 try audioEngine.start()
 catch 
 print("audioEngine couldn't start because of an error.")
 
 messageField.text = "Say something, I'm listening!"
 `
`

please help me out,
Thanks.