As an author, I probably have stylistic similarities from book to book or story to story; I’m sure a forensic writing detective could pick up my fingerprints, so to speak.
(My overuse of parentheses, semicolons and em-dashes would totally give me away–like this, for example!) Still, the narrative voice I use when writing a 19th century historical romance (with densely detailed descriptions of settings, character appearances, and emotions; era-appropriate terminology; longish sentences and generally a slower pace–except during action or some sex scenes, of course) is absolutely not the voice I use when writing a modern, guy-goes-undercover-in-the-mob arc for my online fiction serial. Indeed it’s through that serial that I probably change my narrative style most often, because though I write in the third person, the POV is very narrow. When readers are intended to see the world as seen by my mob informant, the scenes are written with vocabulary he would use, terse descriptions, everything tense and sharp and generally pretty cynical. He exists in a dark, scary world and he doesn’t notice what isn’t important to him, so neither does the narrative.
I remember in one scene from this character’s POV I wrote a line that ended up tripping me up every time I re-read the paragraph while editing: it’s the morning before a big operation was about to go down, and the undercover guy (Jonnie) answered his boss’s “You scared?” with basically “Hell yeah, what the fuck else should I be?” I added a line from the narrator, something like, “Nick [the boss] repeated, ‘what the fuck else should you be’ and nodded in satisfaction, as if Jonnie had just given him the answer to the riddle of the Sphinx.” (I’m totally paraphrasing, I don’t remember the exact wording.)
Anyway when I was editing that scene, I kept stumbling on that line. I knew it was wrong. I knew there was no way Jonnie would know who the hell the Sphinx was–or if he’s maybe heard of the Sphinx in Egypt, he still wouldn’t have heard of the riddle. I didn’t want to lose the line, because as I said, it conveyed precisely the feeling that Nick was giving off. But at last I had to suck it up and removed the reference. I can indulge that kind of thing when writing other scenes for other characters, because some of them are better educated and/or just think more along the lines of similes or metaphors, or know literary/historical references. With this storyline and this set of characters, the line just stuck out like a sore thumb to me. When using a less narrow POV (such as in my novels), I can get away with letting my own voice seep through like that; here, it just betrayed the ‘fourth wall’ so to speak. Even if none of my readers would have noticed (and I think they would’ve), I knew it had to go.
So even though I use a narrator and my readers know I loves me some analogies, word play, and almost cinematic descriptions when I have my druthers, I try not to betray the feel of each scene or the characters who inhabit it. At least for this serial. For my novels, I tend to pull the camera slightly back and let my own voice be heard in the narrative.