Question

How does the structure of the ear allow a person to determine where a sound originates?

Short answer

The pinna enhances high-frequency sounds and concentrates sound waves into the middle and inner parts of the ear through its twists and folds. The pinna also aids in locating the direction a sound is coming from.

Step-by-step solution

Step 1. Introduction

Having two ears is your best tool for determining where a sound is coming from. The brain notices minor variations in the durations and intensities of the incoming signals because one ear is closer to the sound source than the other. This enables the brain to roughly determine the position of the sound.

Step 2. Detailed explanation

The pinna's position and orientation at the side of the head minimize noises coming from behind us. As a result, background noise is less distracting and we are better able to detect sounds coming from the direction we are looking.

The middle ear's tympanic membrane (eardrum) is located at the end of the about 2.5 cm (1 inch) long ear canal. The canal's outer two thirds are home to glands that exude something that resembles wax. The purpose of this earwax and the existing hairs is to prevent dust, insects, and other foreign objects from penetrating further into the ear. Additionally, it aids in keeping the middle ear's humidity and temperature stable.