Comparative evidence

ḱleu̯

• OInd. śru- 'hear' (Whitney 1885: 179); 'listen', 'attend' (to anything), 'give ear' (to anyone), 'learn' (anything); 'hear' (from a teacher), 'study', 'learn'; 'be attentive', 'be obedient', 'obey' (MW: 1100-1101)

References

MW = Monier-Williams, M. 1899. A Sanskrit-English Dictionary. Clarendon Press.
Whitney 1885 = Whitney W. D. 1885. The roots, verb forms and primary derivatives of the Sanskrit language. A supplement to his Sanskrit grammar. Leipzig.