Definitely keep changing your voice. It will decrease your stuttering drastically. Changing your voice is indeed a simple and wonderful fix. Stuttering is a neurological disorder where there is neurological interference from hearing OUR OWN voice. If you do not hear your own voice you will not stutter. Regular stuttering therapy will not usually work and is often harmful. There are several successful stuttering programs that work on breathing where your voice changes and your stuttering decreases. There are also prosthetic devices that are highly effective in reducing stuttering. My kids use Delayed Auditory Feedback (DAF) where you hear your voice a fraction of a second after you speak. I use the Edinburgh Masker where you do not hear your voice as you speak. All these methods are highly effective at greatly reducing stuttering.