ततः शङ्खाश्च भेर्यश्च पणवानकगोमुखाः। सहसैवाभ्यहन्यन्त स शब्दस्तुमुलोऽभवत् ॥

tataḥ śhaṅkhāśhcha bheryaśhcha paṇavānaka-gomukhāḥ sahasaivābhyahanyanta sa śhabdastumulo ’bhavat

Then conches and kettledrums, tabors and drums and cowhorns, suddenly blared forth, and the sound was tumultuous.

In plain words: Then all at once conch shells, drums and horns blare out on Duryodhana's side. The noise is huge.