MCQ : Sound - 1 - UPSC

Wave motion transfers energy from one point to another, often with no permanent displacement of the particles of the medium —that is, with little or no associated mass transport. They consist, instead, of oscillations or vibrations around almost fixed locations.

Sound is nothing more than a local disturbance whose propagation is facilitated by the collisions between particles; This disturbance propagates in a longitudinal wave; imagine one molecule hitting the another molecule, and then that molecule hitting the next molecules, and so forth.
The distance between molecules in solids are very small, i.e., solids are more dense - as compared to liquids and gases. Because they are so close, they can collide very quickly .i.e, it takes less time for a molecule of a solid to ‘bump’ into its neighbour. Solids are packed together tighter than liquids and gases, hence sound travels fast in solids. 

Absorptive material on the back and side walls will help reduce the reverberation time and unwanted reflections. If possible, try to avoid parallel surfaces, which can cause flutter echoes.

In water, the particles are much closer together, and they can quickly transmit vibration energy from one particle to the next. This means that the sound wave travels over four times faster than it would in air, but it takesa lot of energy to start the vibration.

Changing feeble sound to loud sound amounts to increasing the amplitude of vibration as intensity of sound is directly proportional to the square of the amplitude of the sound wave.