Link to purport by A C Bhaktivedanta Swami Srila Prabhupada

Transcript of Bhakti-Shastri class on this verse by Chaitanya Charan

Bg 1.13

tataḥ śaṅkhāś ca bheryaś ca
paṇavānaka-gomukhāḥ
sahasaivābhyahanyanta
sa śabdas tumulo ’bhavat

Word for word: 

tataḥ — thereafter; śaṅkhāḥ — conchshells; ca — also; bheryaḥ — large drums; ca — and; paṇava–ānaka — small drums and kettledrums; go–mukhāḥ — horns; sahasā — all of a sudden; eva — certainly; abhyahanyanta — were simultaneously sounded; saḥ — that; śabdaḥ — combined sound; tumulaḥ — tumultuous; abhavat — became.

Translation: 

After that, the conchshells, drums, bugles, trumpets and horns were all suddenly sounded, and the combined sound was tumultuous.

Then all the different warrior started blowing there conchshells. The war was not just a war but it was fought in a sporting spirit. You have your skills, I have my skills and let us fight so when they are fighting with this kinds of skills they knew that if we die here heroically we attain an auspicious future, so when Kshetriya fought in battle although there was bloodshed and death also but the spirit was fighting in a heroic sporting way and that is why they all became jubilant and let us fight they were all playing different instrument like drums etc bherya is a large drum, paṇavānaka-gomukhāḥ, paṇavānaka is small drums kettle drums, mukhāḥ are horns. 

Sahasaivābhyahanyanta, so just now the talking was going on, Bhisma blew the conchshell and immedeiately everyone who were waiting everyone started blowing suddenly and what happened sa śabdas tumulo ’bhavat, so tumulo is tumult sound was tumultuous and then tumultuous sound spread everywhere.

End of transcription.