According to an aspect of the present disclosure, an ear cup assembly for a hearing protector is provided. In accordance with an example, the ear cup assembly comprises an outer casing, a sealing ring detachably attached on the rim of the outer casing and suitable for sealingly abut against the head of a user around an ear of the user, and a user operable release mechanism for loosening the sealing ring from the outer casing, said release mechanism arranged within the outer casing.