The typewriter signals the end of the row with a ding, and the person moves it for the next line.
A person is typing on a typewriter, then the bell dings and is followed by more typing. A person typing keys on a typewriter, then the bell of a typewriter followed by more typing on the keys. The typewriter signals the end of the row with a ding, and the person moves it for the next line. Typing on a typewriter followed by a ding and then more typing on the typewriter. Typing on a typewriter is followed by a ding and then more typing on the typewriter.