Echos+and+Echolocation

Introduction
An echo is the reflection of sound that is perceived as a second sound. The human brain only holds a sound in memory for 0.1 seconds, therefore any reflection of sound that arrives 0.1 seconds or earlier will be perceived as a prolongation of the original sound, which creates a reverberation and not an echo. Any sound wave that has an interval between the original sound and the reflected sound greater than 0.1 seconds will create an echo.

Occurrence of echoes
Assuming SATP and v=343.2

math d=vt \\ d=343.2m/s \times 0.1s \\ d=34.32m math We then divide this distance by 2 as the sound must travel to the wall and back.

Therefore if at SATP, room dimensions must be larger than 17.16m to create an echo instead of a reverberation. The object in question must be over 17.16m away to create an echo.

Echolocation
Echolocation can refer to several topics. Animal echolocation is the biological sonar used by several different types of animals. They place objects by measuring the time delay between the initial sound and the echo, and the intensity of the sound. Human echolocation is the process of humans making sounds and studying their echoes to detect nearby objects. Acoustic location is done by passive or active acoustic location. Active acoustic location involves you creating a sound and observing its echo to determine a particular object's location. Passive acoustic location involves observing the vibration or sound coming from an object to determine the object's location.