Bhagavad Gita: Chapter 1, Verse 19

स घोषो धार्तराष्ट्राणां हृदयानि व्यदारयत् |

नभश्च पृथिवीं चैव तुमुलो नुनादयन् || 19||

sa ghoṣho dhārtarāṣhṭrāṇāṁ hṛidayāni vyadārayat
nabhaśhcha pṛithivīṁ chaiva tumulo nunādayan

saḥthat; ghoṣhaḥsound; dhārtarāṣhṭrāṇāmof Dhritarashtra’s sons; hṛidayānihearts; vyadārayatshattered; nabhaḥthe sky; chaand; pṛithivīmthe earth; chaand; evacertainly; tumulaḥterrific sound; abhyanunādayanthundering


BG 1.19: The terrific sound thundered across the sky and the earth, and shattered the hearts of your sons, O Dhritarasthra.


The sound from the conch shells of the Pandava army shattered the hearts of the Kaurava army. However, no such effect on the Pandava army was mentioned when the Kaurava army blew on their conches. Since the Pandavas had taken the shelter of the Lord, they were confident of being preserved. On the other hand, the Kauravas, relying on their own strength, and pricked by the guilty conscience of their crimes, became fearful of defeat.