The Proto-Indo-European word *k̂leu-
Word *k̂leu-
Meaning hear
See also Proto-Indo-European: *k̂leus- ‘to hear’
Proto-Indo-European: *k̂léutrom ‘a sound’
Proto-Indo-European: *k̂léwes- ‘fame’

Comments
Mallory J.P. and Adams D. (2006)

Other words that might be of interest
*kar- ‘hard’, *l(e)nto- ‘soft’, *meldh- ‘weak, soft’, *mel(h₁)- ‘soft’, *saiwos ‘hard, sharp, rude’, *menkus ‘soft’