weird sound when I give it gas...need advice

I started noticing it a week ago. When I accelerate, it makes a rumbling sound from what it seems like the engine bay. I can hear it with windows up and down. It sounds like air pushing through something in short bursts and it's louder when I give it more gas. I can't notice any performance difference and I really hope it's just a normal sound. Could that be an exhaust leak or is it something normal...It's loudest when in low rpm's and giving it gas and then it just accelerates into shorter/quicker bursts as the car gains speed...I was listening around the engine bay with the hood up and I couldn't tell any difference...my car has 27000 miles so I don't know if it's just the engine breaking in and making a deeper sound? I feel like a noob right now so I need some advice

See I'm hoping I'm just being paranoid...it sounds like short bursts of air. It actually sounds kind of good when I drive next to walls almost like a meaner sound but I hope it's not something bad. Maybe someone will have had a similar problem or has that similar sound It definely didn't do it before