Avoid uncontrolled constriction When the vocal cords are back to normal, either due to the voice rest, speech therapy or an operation, you must learn to use the voice without the uncontrolled constriction that caused the problem in the first place. Being that piano is a solo instrument and is not taught in school most of the time, this happens quite a bit. On learning to read and interpret notation from the earliest possible stages. Instead of clearing your throat to clear mucous let it remain there until it has covered the dry spots on the membranes. Add a balance of Aural tradition and many more people will stay in music. There are many strategies but no magic pill.
And I also learned how to expand my vocal range so I can now hit sky scraping notes easily and with great tone.
All things being equal a non-smoker is generally healthier than a smoker, not only their voices, so there are definite advantages to quitting smoking. When this is done the voice is fine and sounds normal. Maybe take a Music for People workshop some time. The piano is usually the first thing that comes to mind when you think of putting your child on path to musical knowledge. A year of musical instruction can quickly go down the tubes over the summer vacation if students do not find small ways to play once in a while.