It is often said that with a full-face helmet, the noise of the wind is less heard. Certainly! But the noise of the wind does not indicate the thermals!!!
When the ears are covered, completely or partially, the feeling is just different. It only takes a few flights to get used to it, without causing any inconvenience.
Besides, the ears are sometimes covered with open helmets… so the difference with a full helmet is on this plane non-existent.