DIAGNOSIS: It's normal for it to be audible, but excessive spitting usually means the inner pot is overfilled or you're cooking something very starchy (like oatmeal or beans) that foams up.
FIX: First, never fill the inner pot past the Max Pressure Cook line (about 2/3 full). For foamy foods, don't go past the halfway mark. After cooking, let the pot sit for 10 minutes of natural release before you turn the valve to auto release. This allows pressure to drop gently and reduces violent boiling.
IF THAT DIDN'T WORK: Check the small silicone anti-foam shield inside the steam release valve on the lid. It can get gunked up. Carefully remove it (it pops out), wash it, and make sure it's seated correctly. A clogged or misaligned shield doesn't break foam effectively.
HEADS UP: Always keep your face and hands away from the steam release path. The auto release is convenient but it's still releasing steam at high pressure and temperature. Point the back of the cooker away from cabinets and walls.