Vacuum leak or your window is open.
A ferret that make a hissing sound means they are annoyed or irritated
To make a humming or hissing sound, like an arrow or ball flying through the air; to fly or move swiftly with a sharp hissing or whistling sound., A hissing and humming sound.
Geese make a hissing sound.
since you did not go into any great detail about the noise i am going to guess that there is a leak somewhere between the air filter and the intake. possibly the throttle body area.
it makes hissing vocalizations
Snakes are reputed to make a hissing sound.
Could be a "hissing" sound
they make a hissing sound
the air is depleting from your lungs
A hissing noise
They just kinda make a hissing sound and smack their lips. They just kinda make a hissing sound and smack their lips.
All Snakes Make A Quiet Hissing Sound.