How do I get my cat so stop meowing all the time?

He will just sit either outside my door and howl to the point where I can hear him outside, and the neighbors have complained about his meowing, or sit right in the living and make my mother angry because she can never sleep because he annoys her so bad. I give him attention CONSTANTLY (i'm not exaggeration!) and he never shuts up. Hes not a Siamese (they are real talkers lol), hes just a plain black cat with a loud annoying mouth. My mom says if he wont learn to be quiet she is putting him outdoors (we have neighborhood cats and raccoon's everywhere so he will die). And I CANNOT leave my door open for him to socialize with me, because first of all, I have a hedgehog in my room, so It has to stay a certain temperature, and both of them would get hurt. Second of all, He has this thing, where he will take a poop like, under my dresser, or in my closet, or under my bed side table :( He always has food and water and toys so that's no big deal. We once got him a kitten to keep him company but all he did was attack it constantly, hide under the couches, and once she got a little older he would ALWAYS be trying to mount her, so she had to go :/ Any GOOD suggestions?