BOB HIRSHON (host):
Rodent vocal training. I’m Bob Hirshon and this is Science Update.
[SFX: Rat vocalizations]
These birdlike chirps are actually rat calls, slowed down so that humans can hear them. University of Illinois speech scientist Aaron Johnson has been training older rats to vocalize like this more, to learn how to keep human voices strong in old age. Working with rats allows him to closely study the effects of training on the larynx. Johnson notes that in both rats and humans, nerve receptors in the vocal muscles tend to spread out in old age, making them less efficient.
AARON JOHNSON (University of Illinois):
But with the rats that received this vocal training, we found that those receptors weren’t as dispersed, they weren’t as spread out as the control group.
He also showed that rigorous training brought the older rats’ voices back up to a youthful volume. I’m Bob Hirshon for AAAS, the Science Society.