When we talk about voice in writing, it can get confusing because people use the word to mean different things. Let me offer “style of puppetry” as a metaphor to talk about the different forms of voice.
In puppetry one of the first things you have to do when designing a new show is decide what style of puppet you are going to use. By this, we mean the mechanical style. Are you using marionettes? Rod puppets? Glove puppets?
The aesthetic style of a puppet relates to the design elements. Are you trying to look like the puppets are in the style of Chagal or fuzzy like a Muppet?
For writers, this aesthetic voice relates to the narrative tone. You might go for sounding like Jane Austen, or rural Appalachian, or 21st century Anglo-American.
This relates to the small personal idiosyncrasies of the performer. You can hand the same puppet to two different puppeteers and you can totally tell who is working it even if the performer can do an aesthetic match of the original puppeteers voice. The differences are minute details of timing, choice, and movement that all relate to the puppeteer’s background and personality.
Take a look at these two clips of Sam the Eagle, starting with original Sam, performed by Frank Oz.
And now modern Sam, performed by Eric Jacobson.
Eric is a phenomenally good puppeteer, but you can tell that it’s two different people even though most of you reading this aren’t puppeteers. I can point to the use of the eye mechanism, differences in fluidity of neck movement, and other dynamics, all of which relate to individual performer choices.
For writers, those individual choices come from your background, your lived experience, your taste and interests. I can teach mechanical and aesthetic voice, but I can’t teach personal voice. That personal voice though, that thing that is absolutely unique to you as a writer is why you must write.
No one else can write the things you will write in the way that you write them. You have a voice. Use it.