The researchers hope that in the future, voice therapy in aging humans will help improve their quality of life.
Audio Rats like those used in University of Illinois speech and hearing sciences professor Aaron Johnson's study make ultrasonic vocalizations (USVs) that are above the range of human hearing, but special recording equipment and a computer that lowers the frequency of the rat calls allows humans to perceive them. As the recording shows, the USVs sound a bit like bird calls.
University of Illinois speech and hearing science professor Aaron Johnson, who led the new study along with his colleagues at the University of Wisconsin, said that aging can cause the muscles of the larynx, the organ that contains the vocal folds, to atrophy.
This condition, called presbyphonia, may be treatable with vocal training, he said.
The research is published in The Journals of Gerontology.