Is there a way to play a sound note in only one ear of headphone in swift 2.0 using AVFoundation?

Question

I have created a game (Swift 2.0, iOS9) in which a background music is played continuously and various other sounds are played based on user interaction.

But now, I would like to play a certain sound only in the right or left ear-phone, if the player is using head phones. Is this possible using AVFoundation?

Answer 1

This is how you would play a sound in left or right.

import UIKit
import AVFoundation

class ViewController: UIViewController {

    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view, typically from a nib.
        testSound()
    }

    var audioPlayer = AVAudioPlayer()
    let alertSound = NSURL(fileURLWithPath: Bundle.main.path(forResource: "CheckoutScannerBeep", ofType: "mp3")!) // If sound not in an assest
     //let alertSound = NSDataAsset(name: "CheckoutScannerBeep") // If sound is in an Asset

    func testSound(){
        do {
            //        audioPlayer = try AVAudioPlayer(data: (alertSound!.data), fileTypeHint: AVFileTypeMPEGLayer3) //If in asset
            audioPlayer = try AVAudioPlayer(contentsOf: alertSound as URL) //If not in asset
            audioPlayer.pan = -1.0 //left headphone
            //audioPlayer.pan = 1.0 // right headphone
            audioPlayer.prepareToPlay() // make sure to add this line so audio will play
            audioPlayer.play()
        } catch  {
            print("error")
        }

    }

}

Answer 2

You can check if audio is being played through headphones before you play that sound with this function

func headsetPluggedIn() -> Bool {
    let route = AVAudioSession.sharedInstance().currentRoute
    return (route.outputs ).filter({ $0.portType == AVAudioSessionPortHeadphones }).count > 0
}

And you can change the audio to left or right ear with AVAudioPlayer's pan property like this

myAudioPlayer.pan = 1

set it to -1 for left ear or 1 for right ear