Bhagavad Gita · Chapter 1: Arjuna's Despair

Bhagavad Gita 1.13

tataḥ śaṅkhāśca bheryaśca paṇavānakagomukhāḥ | sahasaivābhyahanyanta sa śabdastumulo'bhavat ||

Then conches, kettledrums, tabors, drums, and horns all sounded at once, and the noise was tumultuous.

Modern context

One signal from the leader, and a whole army answers with noise. Loudness spreads quickly through a crowd and can feel like strength. The verse simply reports it: a great din, and nothing decided yet.