weird engine noise?

[02avant]

hey guys, ive recently noticed a interesting noise when my car is at in 2nd at around 3000 rpm and same thing in 3rd.... its a sorta similar noise to a regular rev but slightly more high pitched . This noise doesnt always happen , but ive pin pointed it happening between the two gears mentioned earlier. My check engine light isnt on . I just replaced my cat last week and my car is running great besides this noise ( whatever it is) so i dont know what it could be. if you have any clue as to what please share. thank you

[Seerlah]

Pinpointing where the noise is coming from is helpful. Could be a number of things.

[demonmk2]

clutch fan maybe?

[Crispy222]

turbo spooling, now that your cat is un-clogged.