stock blow off valve? (MSP)

Hi im new to this forum. I just got mazdaspeed protege about 6 months ago and i was want my car to make that blow off sound. How can i use my stock blow off valve to do this or do i have to purchase a aftermarket unit? Any help would be nice Thanks

are you sure it has a blow off valve and not a blow off plate?? the noisy ones have what almost looks like a speaker on the bov, as where normally a stock one will have a small hose fitting that mutes the sound, and vents it under the car somewhere...