Question

how is it possible to detect the filling of a bottle under a water tap by hearing the sound standing at a distance?​

Answer 1

Answer:

As the bottle fills up, the air column or amount of air inside the bottle decreases. ... Also the amplitude or the loudness of the sound will decrease, as the amount of the air column vibrating decreases as the bottle fills up. So with the increase in shrillness of the sound, you can detect the filling up of the bottle.