What type of hearing protection is typically a small, portable device that fits in the ear?

The correct answer is ear plugs because they are specifically designed to fit snugly into the ear canal, effectively reducing the level of noise that enters the ears. Ear plugs are lightweight, portable, and can be easily inserted or removed, making them convenient for situations where noise levels need to be minimized, such as construction sites or loud events.

In contrast, headphones are primarily intended for listening to music or audio and do not serve as protective devices against noise. Ear muffs offer a higher level of noise dampening by covering the entire ear, but they tend to be bulkier and less portable than ear plugs. Soundproof earmuffs may imply an even more specialized form of hearing protection designed for extreme noise environments, but they too are considerably larger than ear plugs and do not provide the same level of convenience for portability.