Valmiki Ramayana Yuddha Kanda Sarga 11 Shloka 9

ततः then, रावणे: as Ravana, सभाम् to the assembly, गच्छति: as he entered, तूर्यसहस्राणाम् thousands of band instruments, महान् high, निस्स्वनः sounded, तुमुलः tumultuous noise, शङ्खशब्दश्च: sounds of conchs, सञ्जज्ञे: broke forth.

Then as Ravana entered the assembly thousands of band instruments sounded aloud. Conchs broke forth producing tumultuous noise.