How does the gun silencer works..?

You may have seen in different movies or in real life,the use of silencer in a gun.You may be surprised or you may have thought that how we can silence a gun,you may think there is a complicated concept beyond making a gun silent.But you should not worrry,because it works on a very simple principle.
       Let us take an example of a balloon filled with air.If you pop that balloon with a sharp things like pin ,it will brust making a loud sound.But if you let the air pass slowly from the end of the balloon it makes a very little noise.This is the basic concept behind a gun silencer.
             Now let us see the firing mechanism of a gun.When we press the trigger,the gunpowder behind the bullet is ignited.It creates a pulse of high pressure hot gases.This pressure forces the bullet to eject through the barrel of the gun.When the bullet exist the end of the barrel,the pressurized gas behind the bullet suddenly get expanded,which makes an extremly loud sound.
         Now when a silencer having the huge volume compared to the barrel is screwed at the end of the barrel,the high pressure gas behind the bullet will get a big space to expand.Which result in fall in pressure significantly.Finally,when the bullet exit through the hole of silencer the final pressure of the gas is much more decreased compared to the original.Therefore it produces much softer sound.