FlyerTalk Evangelist
Join Date: May 2012
Location: MCO
Programs: AA, B6, DL, EK, EY, QR, SQ, UA, Amex Plat, Marriott Tit, HHonors Gold
Posts: 12,809
A321s are just noisy. This is nothing abnormal or special about JetBlue's newer ones. Pair that with the fact that they are relatively underpowered so on transcontinental flights with higher loads they're going to be running at a higher thrust setting.
Coming off the A380 and getting on an A321, it sounds like you're sitting outside. As noisy as they may be though, nothing is worse than the 737.