Final answer:
The external flap of the human outer ear is known as the auricle or pinna, which helps direct sound waves into the auditory canal.
Step-by-step explanation:
The external flap of the human outer ear is called the auricle or pinna. This cartilaginous part is visible on the lateral surface of the head and plays a crucial role in directing sound waves into the auditory canal. The sound then travels through the ear canal to the tympanic membrane, commonly known as the eardrum, which completes the structure of the external ear. Just inside the tympanic membrane lies the middle ear, housing the ossicles (malleus, incus, and stapes), which transmit vibrations to the inner ear, where the cochlea transduces them into neural signals. Thus, the auricle is a vital component of the auditory system, aiding in hearing or audition.