Resources | Subject Notes | Physics | Lesson Plan
An echo is a sound wave that is reflected off a surface and returns to the listener after a short delay. This reflected sound wave is perceived as a distinct repetition of the original sound.
Sound travels in waves. When a sound wave encounters an obstacle, such as a wall, a cliff, or a mountain, some of the sound energy is reflected back towards the source.
The amount of sound energy reflected depends on the properties of the surface. Smooth, hard surfaces like walls and floors reflect sound effectively, creating clear echoes. Soft, porous surfaces like curtains and carpets absorb sound, reducing the strength of echoes.
Several factors can influence the clarity and loudness of an echo:
Phase | Description |
---|---|
Sound Source | A source produces a sound wave. |
Wave Propagation | The sound wave travels through the medium. |
Reflection | The sound wave hits a barrier and is reflected. |
Return to Listener | The reflected sound wave travels back to the listener. |
Echo Perception | The listener perceives the reflected sound as an echo. |
In summary, an echo is a direct result of sound waves being reflected off a surface and returning to the listener after a noticeable time delay.