Noisy Typer is a free Mac app that plays typewriter sounds as you type—just the thing for those whisper quiet work cafés (video). It plays sounds for letter keys, spacebar, backspace, carriage return (enter), and scroll up & down. Noisy Typer was created by Theo Watson of Free Art and Technology (F.A.T.) Lab.
Noisy Typer, Mac App That Plays Typewriter Sounds As You Type