General:
* Loud
* Clamorous
* Boisterous
* Raucous
* Tumultuous
* Bustling
* Lively
More specific:
* For sounds:
* Cacophonous (harsh and jarring sounds)
* Strident (sharp and piercing sounds)
* Earsplitting (extremely loud)
* Thundering (very loud and booming)
* For places:
* Hectic (a lot of activity and noise)
* Bustling (full of movement and noise)
* Chaotic (disorderly and noisy)
* For people:
* Obstreperous (unruly and noisy)
* Rowdy (noisy and disorderly)
The best synonym will depend on the specific meaning you want to convey.