How many hearing protection devices does double hearing protection consist of?

Double hearing protection consists of two hearing protection devices. This typically involves wearing a combination of earplugs inserted into the ear canal and earmuffs that cover the ears. The use of two types of protection is necessary in environments with extremely high noise levels, as it provides greater attenuation of sound and enhances the overall effectiveness in protecting hearing. The dual layers help to minimize noise exposure more effectively than using either type of protection alone, which is especially important in industrial settings or during loud activities.