also: はねおと
noun
The sound of wings flapping or insects buzzing; covers both birds and insects.
鳥の羽音が聞こえた。
I heard the flapping sound of a bird's wings.
蜂の羽音がうるさい。
The buzzing of the bees is annoying.
noun
The sound of a flying arrow; a more specific, somewhat literary use.
矢の羽音が風を切った。
The arrow whizzed through the air.
Compound of 羽 (ha, 'wing') and 音 (oto, 'sound'). The reading はねおと uses the alternative reading はね for 羽.