Simple example of how to play sounds Swift 4

PlaySounds.swift

class ViewController { 
  
    var audioPlayer = AVAudioPlayer()
  
    struct Sounds {
        static let startupSound: String = "soundname1.wav"
        static let downSound: String = "soundname4.mp3"
        static let upSound: String = "soundname3.aif"
        static let saveSound: String = "soundname2.wav"
    }
  
    override func viewDidLoad() {
        super.viewDidLoad()
        playSound(sound: Sounds.startupSound)
    }

    func playSound(sound: String){
        let path = Bundle.main.path(forResource: sound, ofType: nil)!
        let url = URL(fileURLWithPath: path)

        do {
            audioPlayer = try AVAudioPlayer(contentsOf: url)
            audioPlayer.play()
        } catch {
            print("couldn't load the file")
        }
    }
}