Brihat Samhita
सशिखिचातकदर्दुरनिःस्वनैर् यदि विमिश्रितमन्द्रपटुस्वनाः । खं अवतत्य दिगन्तविलम्बिनः सलिलदाः सलिलौघमुचः क्षितौ ॥ २४-१९ ॥
When the clouds give forth soft, low, and mixed sounds, like the cries of the chakravaka bird, and descend slowly across the horizon, they pour forth abundant water, releasing torrents of rain onto the earth.
english translation
sazikhicAtakadarduraniHsvanair yadi vimizritamandrapaTusvanAH । khaM avatatya digantavilambinaH saliladAH salilaughamucaH kSitau ॥ 24-19 ॥
hk transliteration by Sanscript