It takes a great deal of experience to become natural.
As a writer, I want to be able to write anything, from any point of view, with varying voices. So why do I worry about my voice if I must immerse myself in my characters' voices?
|Speaking loudly doesn't ensure your voice will be heard.|
(Image courtesy of: Darwin Bell on flickr)
The importance of a writer's voice could be explained like this:
You read a book and can see that it is skillfully written. It has an interesting plot, strong imagery, likable characters, and all that. Yet it is still, somehow, unfulfilling.
The story is probably lacking the writer's voice.