My voice dropped very significantly following my tracheal shave, my only option months later after no improvement was vocal cord surgery. Apparently if the shave is aggressive (if the Adam's Apple is very dominant) the cartilage ring can weaken, leading to looser chords and a lower voice. My voice was lower than it had ever been. Vocal surgery has helped tremendously, but frankly the commitment required to change my voice continues to be the hardest and most frustrating undertaking ever.
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