clickety clack
/ˈklɪkɪti ˌklæk/
noun
- A rhythmic clicking or clacking sound, like that made by a train moving on tracks or by typing on a keyboard.
- The clickety-clack of the wheels on the rails was steady and soothing.
- The clickety-clack of the train lulled her to sleep.
- I could hear the clickety-clack of the old typewriter from the next room.