A single signal can move the entire military force.

Immediately after Bishama blew the conch shell, the signal did not end with a single sound. Conch shells, large drums, small drums, taiko drums, and trumpets were sounded simultaneously in various parts of the army, transforming into a massive roar that enveloped the entire battlefield.

The battle begins before the weapons even clash. The commander's signal is transmitted to a large number of soldiers, uniting disparate individuals into a single army. This section depicts that moment through "sound." It is a scene where the reality of war suddenly reaches the ears and bodies of all troops.

Japanese Translation from the Geeta Press Edition - Chapter 1, Section 13: "The Roar Echoing on the Battlefield"

Then, the conch shells and drums, and the trumpets with cow-face mouths, Immediately they sounded, and that sound became very loud. || 13 ||

Translation

At that time, a conch shell, a large drum, a small drum, a drum, and a trumpet all sounded together, making a loud noise.

Annotative Translation

Bishma roared like a lion, and blew the conch shell to announce the start of the battle, filling all directions with hope and encouragement.

And then, suddenly, in every department of the military, the conch shells, trumpets, and other military instruments belonging to each commander were sounded.

These instruments resonated simultaneously, producing a terrifying sound, which echoed throughout the entire expanse of the sky.