Some would call it a lofty goal. Dutch Otolaryngologist Marein van der Torn, MD, recently made it his mission to develop a prosthesis that could improve the voices of people who had lost their vocal cords. So in order to achieve this, he researched the possibility of a new type of voice prosthesis that could produce vocal sound. Additionally, he believed that this concept could potentially help females with weak voices: It could strengthen their voice and enable them to achieve a female pitch again.

Occasionally, the larynx, containing the vocal cords, needs to be surgically removed in throat cancer patients. Since the 1980s most of these patients have learned to speak again with the help of a small silicone rubber valve placed between their windpipe and esophagus.

This valve enables patients to use the uppermost sphincter of their esophagus as a sort of vocal chord. However, this alternative voice often sounds gruff and is lower than the natural voice. Female patients, in particular, have cited the low pitch as burdensome. Moreover, if the uppermost sphincter of the esophagus is too weak, then the voice is not strong enough to be properly understood.

Together with the Netherlands-based University of Groningen, Van der Torn and colleagues at the Vrije Universiteit (VU) in Amsterdam developed a new type of valve that produces its own vocal sound. A small silicone rubber flap in the valve, which acts as an artificial vocal chord, produces that sound.

A different flap was developed for male voices than for female voices. The vibrational behavior of these flaps, the air resistance and the sound produced were extensively investigated in vitro. These new voice prostheses were also trialed in a group of patients at the VU University Medical Center and compared against the voices of these patients without the silicone rubber flap.

From these trials, experts concluded that for the time being only female patients with a very weak voice would benefit from the new voice prosthesis: Their voice becomes more powerful and once again achieves a female pitch. However, various practical problems must be solved before the voice prosthesis is ready for public usage.

Source: Netherlands Organization for Scientific Research