Sound - can be used in crazy ways
Tech Star

Sound can be used and applied in several interesting ways. A common observation is when two houses located at a considerable distance, each other during day time we can’t come to know what going on in the other house (whether it be party or music).

 

However, at nights when it is quiet we can make out if a party or loud music is going on there or not. Well this is because of the sound effect and temperature changes. During the day, temperature is high so the sound ways rise and pass over our head and we can’t listen to it but during night they pass at a low level and we can hear it. Interesting, isn't it? 

 

I know it’s a common observation and many people know about it but the reason behind this was new for me too. If you want to observe the activities that is going on in a nearby house just by listening to it then wait for nights and quiet environment. You surely will be successful to some extent. Even the submarine pilots use it to protect themselves from sonar detection. That is cool.