I`m a musician and when I sing (or speak) it sounds like I have a cold (nasal). It would greatly improve my career if I could at least sing back-up vocals. I`ve tried singing lessons and speech therapy and they didn`t help. I`m considering surgery but don`t know what kind of doctor to look for.
You will need an ENT (ear, nose and throat) or Laryngologist. Once you see a doctor you will know if the condition requires surgery or if vocal work should help it. If so, you need to try different teachers and therapists until you find one who knows how to help you. There are many different techniques and practices out there and all of them work for someone but none of them work for everyone.