Pulsing noise when reving in the cabin

[thenewguy]

So since yesterday, there's this weird pulsing noise coming in the cabin. I hear it when revving while parked or under load. Ill let you guys hear it and maybe see if anyone recognizes it. Its very faint but for sure it wasn't there yesterday....or the past 6 months I've owned it for. Its sorta sounds like how when pistons go up and down or maybe lifters but for some reason seems amplified than before. Seems to be coming from the passenger side. I went to looked outside in the engine bay on that side but saw nothing out of place. Does it happen for you guys as well or am i just being paranoid?
https://photos.app.goo.gl/cT4ixN1r8KaCQdcm9

 

[FiveLeeter918]

does it change with the HVAC being on/off? If someone is in the car revving and you're in the engine bay is in more pronounced in another area?

 

[thenewguy]

It doesn't....you know what it sounds like. You know sometimes when you have the fan on and you can hear it, that's what it sounds like. When I rev it up it it just gets faster. I'm gonna have someone rev while I check in the engine bay but haven't had any issues as far as drivability