atmanas taj jighrksatah
karnau ca nirabhidyetam
disah srotram guna-grahah
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
By development of the desire of the great sages to know, the ears, the power of hearing, the controlling deity of hearing, and the objects of hearing became manifested. The great sages desired to hear about the Self.
Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
As stated in the Bhagavad-gita, by advancement of knowledge one should try to know about the Supreme Lord, the summum bonum of everything. Knowledge does not mean knowledge only of the laws of nature or physical knowledge, which are working by the direction of the Lord. The scientists are eager to hear about the physical laws working in material nature. They are eager to hear through the medium of radio and television about things taking place far away from them on other planets, but they should know that the power of hearing and the instruments for hearing were given to them by the Lord for hearing about the Self, or about the Lord. Unfortunately the power of hearing is misused in hearing the vibrations of mundane affairs. The great sages were interested in hearing about the Lord through Vedic knowledge and nothing more. That is the beginning of aural reception of knowledge.