Disorders in which the pitch is too high are most commonly seen among men and are often the result of mutational disorders, scarring or atrophy of the vocal cords. Disorders in which the pitch is too low most often result from anabolic hormones or hormonal imbalance (such as adrenocortical syndrome) and are most often seen among females. Individuals undergoing male-to-female sex reassignment surgery may also seek treatment to raise the pitch of the voice.
The pitch of the voice is determined by four main factors. These include the length, tension, and mass of the vocal cords and the pressure of the forced expiration (also called the subglottic pressure). Attempts to surgically alter the pitch of the voice focus mainly on two of these factors: mass and tension.
The tension on the vocal cords can be altered to raise or lower the pitch of the voice. To lower the pitch of the voice, a procedure called a thyroplasty can be performed in which a small vertical strip of cartilage is removed from one or both sides of the thyroid cartilage in the neck. This relieves tension on the vocal cords and lowers their pitch. This procedure is conducted under local anesthesia and the patient is asked to phonate during the operation to ensure that the desired pitch is obtained.
Raising the pitch of the voice can be accomplished through cricothyroid approximation or by making a longitudinal incision of the vocal cord. The cricothyroid muscles are two small muscles that connect the cricoid and thyroid cartilages. When they contract, the two cartilages come close together (approximate) and this causes the vocal cords to stretch which raises their pitch. In approximation surgery, the cartilages are exposed under local anesthesia and sutures or miniature titanium plates are placed to bring them closer together. Like the thyroplasty, the vocal cords themselves are not touched during the procedure. Alternatively, a longitudinal incision can be made in the vocal cords. As they heal, the resulting scar causes the vocal cords to stiffen which raises their pitch.
Decreasing the mass of the vocal cords also raises the pitch of the voice. This can be accomplished by injection of the vocal cord with a steroid suspension or through evaporation of part of the vocal cords with a carbon dioxide (CO2) laser. A local injection with steroid will cause part of the vocal cord to atrophy which then raises its pitch. A laser can also be used to vaporize portions of the vocal cords. The resulting decrease in mass and increase in stiffness due to scarring significantly raises the pitch of the voice.
There is an effective procedure using the CO2 laser for patients who have undergone male-to-female sex reassignment surgery. This endoscopic surgical procedure, called "LAVA" for LASER assisted voice adjustment, is performed under general anesthesia and takes about forty-five minutes. Patients go home that day and are required to rest their voices for the first 48 hours following surgery. Most patients are ready to return to regular activity within one week. Over the next several weeks, the patient may be hoarse but the pitch will ultimately stabilize by about three months. Therefore, if a second procedure is required, it will not be performed for at least three months after the first procedure. The pitch can be raised by 100 Hz or more and sounds very natural during conversational speech. Because the procedure is not reversible, it sometimes takes two (and sometimes three) rounds of treatment to achieve the desired rise in pitch.
Note: We are sorry, but the LAVA prodedure is no longer offered by UCSD Medical Center.