It took me a while, but I have been able to cut down on my more noxious tendencies. I have learned not to use certain highly opinionated sounding negative words and to instead focus on using mostly positive speech. This comes from learning about salesmanship from a friend of mine who was very good at it that tired (and failed!) to teach me to do it too. So, instead of focusing on a negative trait, you instead learn to focus your speech on positive traits. Thus, instead of saying that someone's dress or whatever makes them look fat, find something that looks good on that person and compliment that instead.
As far as regulating the volume of your voice, I don't know what to say. My voice has always been sort of loud and my parents relentlessly criticized me for it in childhood. I don't know if I have fixed it now or if no one says anything anymore due to my age.
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Uncertain of diagnosis, either ADHD or Aspergers.
Aspie quiz: 143/200 AS, 81/200 NT; AQ 43; "eyes" 17/39, EQ/SQ 21/51 BAPQ: Autistic/BAP- You scored 92 aloof, 111 rigid and 103 pragmatic