Final answer:
The structures that stick out from the sides of the head are called ears. They are part of the external ear structures, including the auricle and ear canal, which function in hearing and balance.
Step-by-step explanation:
The structures that stick out from the sides of the head are called ears. More specifically, they are comprised of external ear structures that include the auricle (also known as the pinna) and the ear canal leading back to the tympanic membrane (eardrum). The ears serve the function of collecting sound and are also involved in the sense of balance. The other options presented, such as the nose, eyes, and mouth, represent different facial structures with distinct functions: the nose facilitates breathing and smell, the eyes allow for vision, and the mouth is the gateway to the digestive system and facilitates speech.