Maybe a sea lion with gas? Mermaid? Roadguy? Bullet the road dog?

 -----Original Message-----
When all of a sudden I hear "Push" the sound of suddenly escaping air or
some other substance that was under pressure.

After maybe 60 seconds it stopped.
If not, does anyone have any idea what else could make such a sound?

It's kind of like the air release on some vehicle with air brakes.

A quick, short release of pressure.

I'm stumped.