I don't think writers should be afraid of experimenting with different voices, or of evolving. You'll find an approach and style that works for you and for the stories you are writing.
Have any one ever felt concerned they may lose their unique literary voice?
No. Your voice is what it is, you can develop it as Taz says to be more clear and consistent, but I don't think you can alter it much, and I'm sure you can never lose it, so long as it's your natural voice and not one you're trying to effect. In a story, each character's dialogue and thoughts should be different, but I don't think that's the same thing as altering your own voice.
Yes, I worried about that when I was trying to figure out what my voice sounds like. I'd figured that an author must follow self-imposed rules to maintain a distinctive voice. Then I realized changing voices for different works is more fun than following rules, and I don't often care if the reader hears only the narrator, not me as its writer.
No. I don't think a literary voice is a fixed thing anyway. .
Have any one ever felt concerned they may lose their unique literary voice?
No. I don't think a literary voice is a fixed thing anyway. It will likely vary with where you are in your life and with the nature of what you are trying to write. If I'm writing a YA fantasy novel from the narrative viewpoint of a 17 year old, I'd be using a different voice than if I were writing an omniscient pov novel in a different, or even the same, genre (and thus maybe using my own natural voice). I suppose there are ways one's inner personality, tastes, values, experiences, and attitudes will come through, but those are things that evolve over one's lifetime too. And I might try to alter some of those things, depending on the story I am writing and through whose eyes I am showing it. Voice might even change within a book if there are more than one viewpoint character, and I am writing in first or a deep limited third type narrative voice.
I can think of certain writers in the genres I read whose work and style are pretty recognizable, but that doesn't mean there weren't changes over the course of their careers or between different works.
I don't think writers should be afraid of experimenting with different voices, or of evolving. You'll find an approach and style that works for you and for the stories you are writing.
When I was younger, I went through a phase when I wanted my stories to sound a certain way. I reread one not that long ago, and it was cringeworthy. The voice didn't match the character/subject at all, and it ended up feeling like a parody.
... your voice is as much a function of your character, tone, etc. as anything that makes you speshul personally, which is the way it should be--the handful of things I've run into that an author does as "their thing" which I assume are in part their idea of their unique literary voice (thinking off the top of my head of McCarthy and his refusal to punctuate like the unwashed masses) tend to look artificial and off-putting to me. YMMV, of course.
I posed the question because in any art form there may be pressure to conform to the conventions that have been established by past authors. I don't know if this pressure might be brought on by some publishers who may want to suggest to prospective authors to alter their voice or style so their work may sell. I, for one, value and respect originality, and it is that originality that is your signature which you should share with the world. Your voice can always evolve or devolve. Devolve to me is when you compromise your artistic integrity to fit in the commercial world.
I posed the question because in any art form there may be pressure to conform to the conventions that have been established by past authors. I don't know if this pressure might be brought on by some publishers who may want to suggest to prospective authors to alter their voice or style so their work may sell. I, for one, value and respect originality, and it is that originality that is your signature which you should share with the world. Your voice can always evolve or devolve. Devolve to me is when you compromise your artistic integrity to fit in the commercial world.
I don't think that reflects publishing for the last 100 years or so.
Publishers and editors are deeply interested in new voices, interesting voices, and true voices.
Hrm. If you are seeking to self publish, i would say it doesn't matter what trade publishers think either way.