Culkas

The roots of culkas, a type of innocuous-looking bramble, have the particularity of closing the inner pavilions of the ears for humanoid races. The decoction made from it is usually sold in the form of a cream. Applying it in your ears reduces your hearing by about 50%, which still allows you to listen to someone talking in front of you, but above all it prevents you from being deafened, whatever is the volume, the inner pavilions closing completely in case of excessive volume.
A creature that coats the inside of its ears with culkas cream gains advantage on all saving throws against being deafened for 1 minute. Applying several doses in his ears accumulates the duration without however reducing hearing by more than 50%.