Bats Helping Researchers Study Human Speech Impairments

Researchers at Texas A&M University are hoping that research they are doing with bats will lead to a better understanding of speech disorders in humans.

Bats are almost constantly communicating with one another, but at frequencies much to high for humans to hear.

The researchers are focusing on a particular species of bats, the Mexican Freetail bats and how they organize syllables into songs and also how their communications are linked to the brains.

They feel that if they can identify the specific areas in the bats' brains that are responsible for their communication, then they could be able to learn more about how a human brain puts together the complex sequences necessary for communication. And once they accomplish that, they can develop hypotheses that can be put to the test about what might happen with speech disorders.

The researchers are taking a look at two different aspects of how bat communicate. In the first one, behavioral studies, they will examine the differences in the sexes and the season to season differences in the communication. The second will be physiology studies where they will try to locate the parts of the bats' brains that are activated during communications.

The Mexican Freetail bats sing in ultrasonic frequencies that are just above the highest range a human can hear at, so close in fact that humans can hear little bits of their songs when the bats go to the lower end of their range.

There is a good reason why bats use such high frequencies. It is because they have the ability to echolocate, which means that they can project sound and then tune in on the echoes from the sound to figure out what direction a object is from them and also how far away it is. As the frequency of their signal gets higher, the more detailed picture it gets of its surroundings.