As a kid it was funny and maybe a bit weird how my mom could and would easily change her demeanor when switching from being casual/informal to being more “professional”. Her diction and pronunciation changed. The texture of her voice changed. Maybe even her facial expression. We never spoke about why she did it, just entertained that she did. When she calls customer service or if you called her at work you would think that she were a white woman. And it’s not so much the choice of words or hitting every letter in the word just right.
People always get caught up on being told they “talk white” and thinking it means they speak "proper" American English as opposed to something a little less acceptable, say, African American Vernacular English. While it may be true, I don’t think it captures the whole picture. White people can and do speak just as "improper" as Black and Brown people. They have just as much slang, accent, fillers, and slurs. The difference I notice is a certain timbre of voice. It's hard for me to explain but many white people and many Black/Brown people have a distinctly different texture when speaking. Someone can clearly be Black/Brown to me even if they have all the components that are typically said to be white (diction, pronunciation, etc.).
It was a skill that I picked up and understood just by watching my mother. I can and do use it and it’s usually an automatic reaction, many times I'm not doing it consciously. I do it on the phone when talking to tech support, customer service, on a job interview, and talking to police. Always aiming to be a more respectable negro, you know, worthy of being considered. My tragic flaw being that I hate wearing formal or business attire.
I did this when I’d enter a whiter environment. It's not only changing my voice and the way I talk. I consciously hold a different facial expression and change my body posture. I also like to wear my glasses. I figured, if I look less masculine and like dork then these little changes would make me seem less menacing.
I care a lot less about this stuff today. I’ll still use the eyeglasses sometimes but honestly, none of that matters. At the end of the day, my skin is Brown and that’s really all the world needs.