A person's ears. As you may have guessed, the ear emoji can be used to describe anything related to hearing or listening. It can be used to listen, or to hear something. For example, it may mean hearing something, trying your best to hear what is being said, or enjoying hearing something (such as the sound of water running) or someone (talking or singing).
Ear was approved as part of Unicode 6.0 in 2010 and added to Emoji 1.0 in 2015.
U+1F442
? Ear