Narrative voice, to me, is the flavor of the language in which the narrator speaks. If you could 'listen' to the narrative, what would it sound like? Stuffy like a full-of-himself English Lit professor, full of big words and little meaning? Twangy like a back woods redneck? Warm and cozy like listening to Grandpa tell a story?

The narrator, in order to keep the reader interested through the necessary narrative summary, needs to have an at least interesting enough voice to keep the reader from nodding off between active scenes, IMO.

Character voice would be similar, in that each character would have a distinct way of speaking or expressing himself.

Hope that answers your question.

Welcome to Hatrack.

It would definitely be boring without one--like listening to the monotonous out-loud reading of barely literate 4th graders. Also, if your story sounds too much like a synopsis, it's quite possible it IS too much like a synopsis.

Try this exercise:

Write a scene from your story in first person POV. Tell what the character feels and thinks and sees and hears and smells. Show your readers something happening through this character's senses and observations.

Next, rewrite the same scene in third person. What you're trying to do is retain that sense of immediacy and excitement that first person gives you, but through the eyes of a detached observer who sees and hears and smells and thinks through the mind of the person who was ACTUALLY telling the story in the First Person exercise.

I hope that makes sense. I'm awfully tired. Bedtime for Baby. ZZZZZZZZZZZZZ