Phonosurgery is a set of specialized surgical procedures to improve or restore the voice by modifying the vocal folds. The different types (I–IV) refer to Isshiki's classification system, which describes how the vocal fold is repositioned or reshaped:

Type I (Medialization): Moves a paralyzed or weak vocal fold toward the midline to help it close during speech.

Type II (Lateralization): Used to treat spasmodic dysphonia by moving the vocal fold slightly outward to reduce tension.

Type III (Relaxation): Shortens the vocal fold to lower pitch, often used in transgender voice surgery or certain hyperfunctional voice disorders.

Type IV (Tensioning): This technique lengthens the vocal fold to raise pitch. It is sometimes used to feminize the voice or strengthen weak vocal folds.

These procedures are typically performed under sedation anesthesia, though some can be done under local anesthesia with the patient awake (to fine-tune voice outcome). Recovery includes voice rest for several days, followed by voice therapy to train the new vocal dynamics. Most patients notice a gradual improvement over weeks. Risks include hoarseness, over- or under-correction, or need for revision surgery, but outcomes are generally excellent when tailored to the individual's voice goals.