The outer ear both locates sound sources and boosts certain frequencies

Evidence

The auditory canal is approximately 25 to 35 mm long from the concha to the tympanic membrane, more commonly known as the eardrum. The outer ear has an acoustic effect on sounds entering the ear in that it helps us both to locate sound sources and to enhance some frequencies with respect to others. — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 517

Categorization

• DEFINE: Clarifies what the auditory canal and concha are and their acoustic role.