//funzione di suono
  
  import AVFoundation
  var player : AVAudioPlayer!
func playSound(nameOfSound : String) {
     
        guard let url = Bundle.main.url(forResource: nameOfSound, withExtension: "mp3") else {
     
            return
        }
        
        do {
            try AVAudioSession.sharedInstance().setCategory(.playback, mode: .default)
            try AVAudioSession.sharedInstance().setActive(true)
            print("debug 3 ")
            /* The following line is required for the player to work on iOS 11. Change the file type accordingly*/
            player = try AVAudioPlayer(contentsOf: url, fileTypeHint: AVFileType.mp3.rawValue)
            
            /* iOS 10 and earlier require the following line:
             player = try AVAudioPlayer(contentsOf: url, fileTypeHint: AVFileTypeMPEGLayer3) */
            
            guard let player = player else { return }
            print("debug 4 ")
            player.play()
            
        } catch let error {
            print("Error was detected")
            print(error.localizedDescription)
        }
    }
    
    //use this to play the sound
    playSound(nameOfSound: "Sound")