Does a song sound different when you are moving? The Doppler effect changes the pitch of a sound depending on motion. You can hear it happen with nothing more than a phone and your own feet. You play a song on a computer or phone. First stand still and listen carefully. Notice the pitch and tone. Then move quickly while listening to the same song. The sound shifts slightly as you move. To hear exactly the sound being played you must stay perfectly still. As soon as you start moving the pitch you hear no longer matches the pitch being produced.