I don't think there's much of anything you can do really. It's just what happens. I just learned to use the sound to make sure my breaths were even and it became sort of like my own personal sound machine or white noise.
There will be things about using a CPAP that you will just have to get used to. It's going to be very different than the way you have always slept before. But, it will also provide you with the right and necessary kind of sleep that we were all meant to get.
You will have to experiment with both types of masks, their straps and the position on your head and face, and your sleeping positions. Even how you lay your head on your pillow.
The good thing is, that you CAN adjust. Patience, a positive attitude and a desire to be healthy again will go a very long way in helping you become adjusted to sleeping with your CPAP. And regardless of how it feels here in the beginning, you MUST use it every night, faithfully. Skipping nights will only make it that much longer before you get used to your new sleeping habits.
Good luck and we're here to answer any other questions you may have and will listen and understand should you need to vent. We've all been right where you are now.

Liz covered it very well, it's a matter of getting used to it should only take a few nights. Just try to relax and go with it rather than try and fight it. Keep us updated on how your going.

Maureen, I use the nasal pillows. I find that to avoid the noise of rushing air, I need an unobstructed space in front of the air escape vent, and the the nasal pillows need to be pointing in the right direction (both outside and inside) and the nasal pillows have to be just barely inside my nose. And the hose needs to be anchored to me to avoid the weight of the hose pulling the mask out of alignment.

One more thing; the nasal pillows must be the right size. I'm a chubby girl but my nasal pillow size is XS. Go figure.

If all of these are right, there is NO SOUND at all. Oh yeah, I made a chin strap of 3 inch heavy elastic that holds my mask in place. Velcro keeps it closed at the top. It took a few tries to get it right.

Don't give up dear. You'll get it. The solution is just at your fingertips.

when going to sleep, get comfortable in bed, you don't have to lie on your back, breathe deep and slow
earplugs may help you with the noise