General:
* Babble: Meaningless or incoherent talk.
* Jabber: Fast, excited, or incoherent talk.
* Prate: Talk idly or at length.
* Gabble: Talk rapidly and indistinctly.
* Clatter: A series of rapid sounds, often referring to noisy talk.
More specific:
* Gossip: Talk about other people's private lives.
* Small talk: Light, informal conversation.
* Banter: Playful or humorous conversation.
* Rambling: Talking in a long-winded or aimless way.
* Gushing: Talking enthusiastically and effusively.
Figurative:
* Buzz: A lively and energetic atmosphere.
* Hum: A steady and low-key level of activity.
The best word to use will depend on the specific situation and the tone you want to convey.