Listening with a single ear enables one to localise a sound source because:

Question

Quizplus · Accepted Answer

Filtering and delay of sounds induced by the pinna (the outer part of the ear) vary with the angle between the source and the pinna, allowing the brain to interpret the location of the sound source even with a single ear. This is because the shape and form of the pinna affect how sound waves are captured and directed into the ear canal, creating cues that the brain uses for localization.

Listening with a Single Ear Enables One to Localise a Sound