Humming

a.	1.	Emitting a murmuring sound; droning; murmuring; buzzing.
n.	1.	A sound like that made by bees; a low, murmuring sound; a hum. Hummingale lively or strong ale. Humming-bird moth (Zool.) a hawk moth. See Hawk moth, under Hawk, the bird. - Dryden.

Noun	1.	humming - a humming noise; "the hum of distant traffic" Synonyms: hum
	2.	humming - the act of singing with closed lips

bel canto, birring, bombilation, bombinating, bombination, booming, bravura, burring, busy, buzzing, choral singing, coloratura, croon, crooning, droning, folk singing, fussy, hopping, hum, hustling, intonation, lively, low rumbling, lyricism, operatic singing, popping, purring, scat, scat singing, singing, sol-fa, sol-fa exercise, solfeggio, solmization, song, thrumming, tonic sol-fa, vocal music, vocalization, warbling, whirring, whizzing, yodel, yodeling