Is it possible to have surgery or vocal chord transplant to change your voice?

Yes and no: If you simply don't like your voice, speech therapy is the first step. If this is not beneficial or if you are hoarse, see an ENT physician for endoscopy and consideration of more aggressive treatment (injection augmentation of the vocal cords, other surgical treatment, etc.). Not all ents treat aggressively for simply not liking your voice, however, and transplant is not feasible at present.