Generally no it doesn't change your voice - var is considered the "least aggressive" of the AAS out there - that said it is still an androgen and the impact of it on your particular body chemistry is always your own personal experiment. I would say if it affected anything you would notice it mostly in your singing voice in the higher range. So "statistically" I'd say you have a much less chance than using anything else, but never any guarantees. And also the off chance that whatever you got that you think is var, might not be.