Oh. Interesting! I didn’t know that about the effects of estrogen shortening the cords.
Think how swollen your hands get if you continually rub them together. Then picture the vocal chords swelling. Sometimes that produces hoarseness (If just the vocal chords swell). But other times, if the thyroid is swollen and presses against the voice box, it just limits the area that can vibrate which produces a higher pitch.(It can be accompanied with a hoarse sound) Either can result in nodules, which are basically callouses.
Always have student check their body temperature. If it averages in the 97.degree range it is a sign of thyroid problems. It's why people who talk a lot in their profession, and don't speak from the diaphragm, need a voice coach. Speaking from throat causes it to swell.