All L2 pilots will probably admit to suffer from tinnitus to some extent, some more than others. Biggest challenge is that the high frequency noise from the intakes goes right trough the scull, totally bypassing any sophisticated headset. Just flying with a cap on makes a big difference, and lately winterliners for construcionwork helmets has become quite popular to put over the cap.
The L2's in Norway now have sound proofing material in the cockpit ceiling, cutting the noise by a couple of db. I'm currently looking into replacing my Peltor with a helmet, which must be lightweight and comfy.