Sound travels faster in solids and hence is more clear, but when there is a lot a noise we close our ears by putting our fingers on it, and we then hear lesser volume of sound, though our finger is a solid?or in another words , y a wall acts as a barrier 4 the sound waves[ means that we cannot hear anything clearly if there is a wall between the source of sound and our ear.?

Hi Amin,

It is because the wall acts as a source for reflection.

It is true that sould travels faster in solids, but in that case the origin of the sound must be from the solid.

As in case of noise the origin of sound is not in the finger it will not allow sound to pass through.

(More over the finger is not entirely solid. It has blood inbetween which is a fluid). And sound travels slowly.

Actually try putting your hand in both the ears. The surrounding noise level will of course be reduced. But you can hear the sound of vibration occuring between your hand and your ears very clearly.

Hope it helps.

Wish you all the best.

Regards,

Ashwin (IIT Madras).