sound of rustling leaves
Refers to the gentle sound made by leaves moving in the wind or being brushed against.
In the forest, only the sound of leaves rustling in the wind could be heard.
On an autumn night, every step on the fallen leaves made a dry rustling sound.
Compound of 葉 (は, leaf) and 音 (おと, sound). The reading はおと is a straightforward combination of the kun'yomi of both characters.