Why is Thunder loud?
Thunder is so loud that it resembles a large explosion most of the times. When lightning is created in the sky, the sound that is generated in it comes out as thunder. The lightning that is created is so hot around 50,000 degrees C. The lightning makes the surrounding air hotter and hence the heated air expands very rapidly. These fast changes that happen in the air are heard as thunder. The vibrations in the sky are understood by our brain in the form of a sound or thunder.
We can hear others speaking when their voice make some vibrations in the air. The vibrations reach our ear and we hear them as sound. The vibrations that are created in the air due to the lightning are far higher than that created by the voice of a person. That is the reason why the thunder is so loud and we generally do not allow our ears to listen to the thunder.
Lightning is distributed to many different directions in the space. Similarly the thunder is also not heard from one part of the sky but, it rumbles from various directions in the sky. Though the thunder is created from the lightning originated from one part of the sky, rumbling of it makes it to be heard from all the directions. The sound resonates to create a deep, long and rolling sound which is heard by us as very louder. Thunder occurs after lightning appears in the sky as light travels faster than sound. After the lightning appears, if the thunder is heard 5 seconds later, it means the lightning is one mile away from us. It is said that thunder or sound takes 5 seconds approximately to travel one mile.
Thunder is heard louder as the lightning created sound rumbles around, spreads and get echoed due to the buildings and ground and hence it is heard loud.