स्वरभेदो भयहर्षक्रोधजरारौक्ष्यरोगमदजनितः । श्रममूर्छमदनिद्राभिघातमोहादिभिः प्रलयः ॥ ९९॥
Change of Voice (svara-sāda) and Fainting (pralaya) : Change of Voice (svara-sāda) occurs as being due to fear, joy, anger, fever, sickness and intoxication, and Fainting (pralaya) due to too much toil, swoon, intoxication, sleep, injury, astonishment and the like.
english translation