Sound propagates maximum in

Which of the following are used to study the growth of foetus inside the mother's womb?

A musical instrument is producing a continuous note. This note cannot be heard by a person having a normal hearing range. This note must then be passing through:

We can distinguish between the musical sounds produced by different singers on the basis of the characteristic of sound called :

The pitch of sound depends on:

Eardrum is a part of:

When we change a feeble sound to a loud sound, we increase its:

Choose the correct answer. Sound can travel through:

To an fro motion of an object is called

Noise pollution is harmful for