'Singing rats' show training might help aging voices
CHAMPAIGN — Mother Nature does a number on our voices as we get older, but a new study at the University of Illinois suggests vocal training might help.
The research was done with rats, which have vocal folds (chords) similar to those of humans and face some voice changes similar to humans as they age, said UI speech and hearing Professor Aaron Johnson, who led the study with colleagues at University of Wisconsin.
A former classical singer and voice teacher, Johnson said it's known that exercise strengthens limb muscles but not whether vocal exercise can strengthen voice muscles.
To see if vocal training would make a difference, male rats were placed in a cage with a female rat. Then, the female was taken away and the males were given treats when they vocalized, Johnson said.
The rats' ultrasoninc calls were above the range of human hearing, Johnson said. But special recording equipment was used to pick up their sounds, along with computer equipment that lowered the frequency, so the rat calls (which sounded like bird calls) could be played back in an audible form for people.
Johnson said these "singing rats" provided the first evidence that vocal use and training can change the neuromuscular system of the larynx.
The older rats that didn't get vocal training proved to have lower average vocal intensities than both the vocally trained rats and the young rats that hadn't been trained.
Researchers also found a breaking apart of the neuromuscular junction that occurs in the elderly was less for older rats that received the training.
People go through their most dramatic voice changes during childhood and adolescence, and then changes level off for decades. Then with aging, loss of muscle mass and mucous membrane thinning also begin to affect the larynx, which contains the vocal folds, according to the American Academy of Otolaryngology-Head and Neck Surgery.
Degrading of the neuromuscular junction, an interface between the nerve that signals the vocal muscle to work and the muscle itself, also contributes to aging-voice symptoms such as breathiness or weakness in the voice or being too fatigued to finish a conversation, Johnson said.
Aging isn't the only culprit, he said. Smoking, asthma, allergies, chronic obstructive pulmonary disease, lumps on vocal folds, and head and neck cancers can also cause voice problems, Johnson said.
He plans to continue his research with another study coming up soon in which he'll use and MRI and high-speed imaging to study changes in vocal folds, and he'll be recruiting younger and older adults for that, he said.
Another study he hopes to do in the future would involve the effect of group singing training on vocal function in older adults, he said.
Meanwhile, adults don't have to just sit back and wait for age-related voice changes to happen, according to Johnson. There are things people can do to help protect their voices.
"The evidence we have points to use it or lose it," Johnson says.
A pamphlet he has from the University of Utah's National Center for Voice & Speech advises the following:
— Drink 48-64 ounces of water a day to keep vocal folds hydrated and less prone to damage.
— Sip water if you clear your throat a lot, because frequent throat-clearing can irritate vocal fold tissues.
— Try relaxation techniques to avoid stress, which can lead to forceful voice use and possible tissue damage.
— See your doctor about acid reflux symptoms, which can lead to voice problems. Hoarseness and breathiness may also be a sign of something wrong.
— Caffeine, alcohol and some medications dehydrate the vocal folds and reduce their ability to maintain vibration, and smoking irritates the lungs, larynx and vocal tract.
— Talking loudly over long periods can lead to a voice disorder, so consider getting a microphone or vocal training.
Johnson also advises older adults to read out loud to one another, or even out loud to themselves, to keep their voices active. He knows this can be a challenge for older adults living alone.
So maybe talking to yourself isn't so bad?
"I don't think it is," Johnson said.