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Shattering news |

How to restore people’s voices

INJURY, disease or sheer old age mean that as many as 7% of Americans (and, presumably, a similar proportion of the population of other countries) have some kind of voice disorder caused by scarring of their vocal cords. Such scarring makes the cords stiff, and stops them producing sound in the normal way. But that could be overcome if a method were found to restore the cords’ flexibility.

Robert Langer, a pioneering biomedical engineer at the Massachusetts Institute of Technology, and his colleagues think they have one. They have developed a material that mimics the characteristics of natural vocal cords and could thus help restore distorted voices.

To make their new material, Dr Langer and his team took polyethylene glycol, a substance widely used in the cosmetics industry and thus known to be safe, and altered the chemical linkages between its molecules.

This allowed them to control the polymer’s viscosity and elasticity. After some trial and error, as they described on August 20th to a meeting of the American Chemical Society held in Philadelphia, they hit on a mixture which matches the traits of human vocal cords.

Laboratory tests have shown that when air is blown through a model of the vocal cords made from this material, the model responds in the way that real cords do. Leer más “Good vibrations –”