Does anyone else hear a muted siren sound when letting off the throttle?

I can't really think of a good way to describe this sound I'm noticing but lately when coming off throttle sharply at 20+ mph I can hear what sounds like a whoosh of air or a muted siren winding down. This being our first prop boat I didn't know if this was just a normal sound of maybe the prop slowing down quickly against the water or something like that. I will try and get a short video the next time we're on the boat to better describe it. I don't think it's a sound like something is wrong but just curious what I'm actually hearing. It is definitely coming from the rear area of the boat. If I slowly let off the throttle I don't notice the sound. It only seems to happen if I pull back to idle quickly while traveling above planing speeds. Kind of like a blowoff valve in the water if that makes any sense lol.

Could it be the engine accessory belt slipping just a little bit with the rpm change?

Hmm It doesn't have a squealing belt sound. More like a whoosh kind of sound. Maybe it's the K&N style air filter I'm hearing? I'll let my dealer know about it since I have it in the shop for the ballast relay module issue anyways. I'm sure they will do a water test to make sure the ballast pumps are working again and they can do some test runs to see if the noise is normal or not.