How does Tabla produce sound ?

In Tabla (or any percussion instrument, whereon leather is fitted), sound gets generated, when the leather surface thumped, wither by fingers or palm. The waves thus created travel in two dimensions. These waves then reflect from the leather surface periphery, and so produce standing waves. When the wave is two dimensional, node converts into a line.

There are various air layers floating parallel over the leather surface of a percussion instrument. When this leather surface vibrates, air layers also vibrate. When air layer travels up, it also pushes the adjacent layer in upward direction. However, as said earlier, due to the other parallel air layers floating over the leather surface, this layer (i.e. air layer travelling up) can’t travel freely in upward direction. Thus, it gets compressed between the very next upward air layer and the leather surface. Thereafter, it too starts pushing the other floating air layers in upward direction, causing their compression. Subsequently, this compression starts its travel in the air. In the meanwhile, the leather surface loses its tension and comes down. Air layer on it thus gets pushed down, i.e. it expands as the pressure releases. When this leather surface attains its original position, this expanded air layer is pushed upwards. Thus, the pulse due to the compression and expansion begins to travel ahead. As this pulse is dependent on the vibration of leather surface, its frequency is similar to the leather surface frequency. In this way, the vibrating air layer reaches to the listener and so he/she becomes aware about the sound. Thus, can be the description of ‘how does tabla produce sound’.