I used to have a very severe stutter into my late 30's and I am still in my late 30's and I am now making cold calls to businesses for my company and successfully doing it. It took a massive amount of hard work and changing how I think and changing everything about my speech...I believe more than anything else that stuttering is more of mental disorder than a physical disorder. I tried speech therapy for years with basically no results. Once I set out to conquer it I did.