PUMPA - SMART LEARNING
எங்கள் ஆசிரியர்களுடன் 1-ஆன்-1 ஆலோசனை நேரத்தைப் பெறுங்கள். டாப்பர் ஆவதற்கு நாங்கள் பயிற்சி அளிப்போம்
Book Free DemoAn echo is a sound that is reproduced due to the original sound being reflected off from various rigid surfaces such as walls, ceilings, mountain surfaces, and so on.
Shouting near a mountain
You can hear the same sound if you shout or clap near a mountain or a reflecting surface, such as a building. The sound you hear is known as an echo. It is because of sound reflection. In a small room, there is no possibility of echo. This situation does not mean that sound bounces around in a small space. This is due to the fact that smaller rooms do not meet the basic requirements for hearing an echo.
Conditions necessary for hearing the echo:
- Human ears have a \(0.1\) \(-\) \(second\) persistence of hearing. This means that if the time interval between two sounds is at least \(0.1\) \(s\), you can hear both of them. As a result, the time gap between the original sound and the echo must be at least \(0.1\) \(seconds\).
- The above criterion can be met if the distance between the source of sound and the reflecting surface obeys the following equation:
since,
As a result, the minimum distance required to hear an echo is part of the magnitude of sound velocity in air. If you consider the velocity of sound as \(344\) s, the minimum distance required to hear an echo is \(17.2\) \(m\).
Application of echoes:
- Some animals use sound signals to communicate and locate objects over long distances.
- Obstetric ultrasonography, which creates real-time visual images of the developing embryo or foetus in the mother's uterus, uses the echo principle. Because it does not use any harmful radiation, this is a safe testing tool.
- In any medium, echo is used to determine the velocity of sound waves.
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