Here is the snapshot:
And the code is here:
UIButton *leftButton =
Here's a Swift 3 version of the most voted answer:
let soundButton = UIBarButtonItem(image:image , style: UIBarButtonItemStyle.plain, target: self, action: #selector(self.soundPressed))
let negativeSpacer = UIBarButtonItem(barButtonSystemItem: .fixedSpace, target: nil, action: nil)
negativeSpacer.width = -5
self.navigationItem.rightBarButtonItems = [negativeSpacer,soundButton]