I am going to play devils advocate. The hoover sound is harmonics and like you said air turbulance. Example.
4.0L ford motor, has that ribbed black dick looking intake tract, straight to a GIANT round airfilter and air box. Its silent. replace it with a traight hunck of aluminum tube with the same inside dia, leave the filter and air box. hoover sound.
same with a 1.8T VW. the ribbed turbo inlet pipe and ribbed baffeled airbox cuts the turbulance down and makes them silent. I put a K&N drop in, into the stock air box way back when i first got the jetta. was silent. MAF read only like 15Grams more under WOT highest boost spike. didnt do shit for performance or sound. Shaved the air box, and then added some more holes to the air box and removed the “ram air” duct. made a tiny bit more sound, Grams pers sec reading at the MAF was the same. Diverter valve was silent too when it dumped. I put a CIA on. Sounded like a hoover, DV dump sounded like a BOV. GPS on the maf only went up about 20 grams over stock. total reading was 280 something IRC. So between the shaved air box and K&N 5 grams difference DIDNT create the sick hoover sound under WOT, I think it had to do with the ribbed dick intake and air box design.
back on topic :thumbup
mileage dropped becasue I drove the balls off it stuntin around town showing off my WOOOT-PSHHHH. :rofl