General antonyms:
* Loud
* Noisy
* Boisterous
* Lively
* Rowdy
* Tumultuous
* Claustrophobic
Antonyms related to sound:
* Blaring
* Clamorous
* Echoing
* Raucous
* Sonic
Antonyms related to behavior:
* Chatty
* Talkative
* Outgoing
* Energetic
* Excited
The best antonym for "quiet" will depend on the specific situation and the intended meaning.