Sound expert Julian Treasure created an online competition to discover the world's most beautiful sound.

What's the most beautiful sound in the world? Is it water rushing? The song of the hermit thrush? Wind rustling through quivering leaves? Renowned sound expert Julian Treasure wanted to know, so he created an online competition to discover "the most beautiful sound in the world." Out of all the submissions, a sample recorded at dusk in Malaysia near a swamp was judged to be the most beautiful sound of all.

"It was a sound of a swamp with a frogs singing. The most amazing, rich recording of just life—teeming life," Treasure said. "And listening to it you really get the sense of nature at its fullest, and most abundant and most exciting."

Here is the winning entry—which we recommend listening to with headphones for the full effect:

Of course, beauty is subjective. Can anyone claim that this is literally the most beautiful sound in the world? One person's beach waves might be another person's singing frogs—but there is no denying this is a spectacularly beautiful sound!