Śrīmad Bhāgavatam 2.3.20

bile batorukrama-vikramān ye 

na śṛṇvataḥ karṇa-puṭe narasya 

jihvāsatī dārdurikeva sūta 

na copagāyaty urugāya-gāthāḥ (Śrīmad Bhāgavatam 2.3.20) 

One who has not listened to the messages about the prowess and marvelous acts of the Personality of Godhead and has not sung or chanted loudly the worthy songs about the Lord is to be considered to possess earholes like the holes of snakes and a tongue like the tongue of a frog.