Why water is poured on the rocket before a rocket launch

Everyone has noticed one thing before rocket launch that the water is being poured on the rocket before it's ignition and the question which comes to our mind is, why the water is poured on the rocket before a rocket launch?.

So it is a result of firing 27 Merlin engines to produce about 5.5 million pound of thrust, which results in lot of heat and sound production. Around 180dB to 220dB of sound is produced during the launch. Around 85dB of sound produced can cause permanent damage to ears. The shock waves produced by the rocket will not only damage the ears but will also damage the surrounding buildings.

In order to suppress the sound the water is poured on the rocket before it's launch, a large water towel which can damp up to 1 million pound of water into the launch pad in just 40 sec in place nearby.

As the energy gets absorbed, they get heated up. Thus energy transforms sound energy to heat energy. By this sound can be damped to about 145dB from 195dB and it also extinguishes the fire caused due to the exhaust of the rocket.