noun / verb
chatter
CHAT-er/ˈtʃætər/
Rapid repetitive vocal or rattling sounds.
He chatters animatedly while his friend listens at the cafe.

Etymology
The Middle English verb imitated quick, shrill sounds and was used both for birds twittering and for people talking idly. That pairing connects rapid speech with talk of little substance.
More examples
- Their cheerful chatter filled the kitchen.
- His teeth chattered in the cold.
- A rapid chatter came from the old fan.
Forms
chatter · chatters · chattered · chattering
chatterbox noun — someone who talks a great deal