Do all iPhones do this?

While using headphones, there is a slight popping or static noise when the keyboard is opened, starting music, starting an app or basically initiating any sound. It's faint, but there. Plug in headphones, make sure mute is off, and swipe to the right to go to search and back to home screen. It's also easy to hear going from contacts to keypad. Happens on all headphones.

iPhone 5-16g