There are three essential elements to hearing:
• Directing the waves of sound inside the inner ear that controls hearing
• Detecting the fluctuations within your ear for the pressure in the air
• Translating all of the fluctuations into a signal your brain is going to be able to interpret and understand
The outside part of your ear works to help capture the sound waves. It is pointed in a forward direction and has multiple curves within it. This specific structure helps your ear to determine where the noise is coming from. If the sound is coming from behind or above you, the sound will vibrate off your outer ear differently than if it were coming in from in front of or below you. Due to the reflection in sound, the pattern for sound waves will vary greatly. Your brain is able to recognize and interpret all of the different patterns and help determine where the sound is coming from.
It is your brain that works to determine the location of the sound based upon the information that enters into your ears. If the noise is coming in from the left, it is going to reach the left ear quicker than it is going to reach the right. You will also notice that the sound will be louder in the ear closer to the sound.