When a sound is reflected from a distant object, an echo is produced. Let the distance between the reflecting surface and the source of sound production remains the same, Do you hear echo of sound on a hotter day?

Explanation

Due to persistence of hearing, we keep on hearing the sound for 0.1 second even after the source of sound has stopped. The speed of sound increases with the increase in temperature. So the speed of sound will be more on a hotter day, The time after which echo is heard will decrease. (Time is Inversely proportional to the velocity of sound). If the time taken by the reflected sound is less than 0.1 s after the production of original sound, then echo is not heard.