Music by Kevin MacLeod. Available under the Creative Commons Attribution 3.0 Unported license. Download link: https://incompetech.com/music/royalty-free/index.html?isrc=USUAN1100381

MacLeod's description:

Genre: Horror
Length: 0:02
Instruments: Synths

Could be breathing, could be the wind, it is very dark, and kind of disturbing. 037
ISRC: US-UAN-11-00381
Dark, Eerie, Mysterious, Unnerving 2007