// Setup input source
  let audioSession = AVAudioSession.sharedInstance()
  do {
      //try audioSession.setCategory(AVAudioSessionCategoryRecord, with: .allowBluetooth)
      try audioSession.setCategory(AVAudioSessionCategoryRecord)
      try audioSession.setMode(AVAudioSessionModeMeasurement)
      try audioSession.setActive(true, with: .notifyOthersOnDeactivation)
  } catch {
      print("audioSession properties weren't set because of an error.")
  }