A team of scientists from the Institute for Cell Biology and Neuroscience at Goethe University has found the process by which brains produce sound. The study, led by neuroscientist Julio C Hechavarria, looked into the brain activity of Seba short-tailed bats just prior to their vocalizations. For more than five decades, bats have been used as models for studying how the human language develops as well as understanding the secrets behind how the brain processes auditory stimuli.
Brain and voice
The bats often find their preferred fruits through the use of an echolocation system. When it wants to communicate with other members of its kind, these bats use a deeper frequency range. “The scientists were able to identify a group of nerve cells that create a circuitry from the frontal lobe to the corpus striatum in the interior of the brain.
When this neural circuit fires off rhythmic signals, the bat emits a vocalization about half a second later. The type of rhythm seemed to determine whether the bats were about to utter echolocation or communication vocalizations,” according to Science Daily.
Scientists trained a computer to analyze recorded sounds and neural rhythm separately. The system then tried to make prognoses based on the different rhythms. When the results came in, the computer turned out to be 80 percent correct in predicting echolocation versus communication vocalizations.
The researchers argue that the rhythm that they observed in the bat’s brain was similar to the one usually seen from the human scalp. From this, they concluded that brain rhythms might be a crucial component in sound production among mammals. By continuing the study of bats, scientists hope that they can bring about a better understanding of diseases like Parkinson’s and Tourette syndrome.
A 2018 research had identified the area in the human brain responsible for controlling the pitch in speech. The study was done on epilepsy patients using a process called electrocorticography. The subjects were asked to repeat a sentence several times, with a different word being emphasized each time.
“The team found that neurons in one particular brain area — the dorsal laryngeal motor cortex — were activated when a pitch was altered. When the pitch became higher, the area showed more activity. As well as examining activity, researchers also electrically stimulated neurons in this area. This caused the larynx muscles to flex and even prompted a vocal response in some patients,” according to Medical News Today.
Interesting facts about the human voice
Men tend to have more baritones than tenors or basses, whether they are speaking or singing. When it comes to female vocals, the middle range of the mezzo-soprano is the most common. Children are often trebles, with a range of approximately a soprano. When they grow up, the male vocal folds become thicker and longer than their female counterparts.
There is also a strong connection between the voice of pregnant women and the babies they carry in their wombs. “At 25 weeks of development, your baby can already recognize and respond to your voice… Once they’re born, babies also show a clear preference and recognition for their mother’s voice over other female voices that they hear,” according to The Healthy.
When people have a sore throat, they usually whisper in a bid to not hurt their throat anymore. However, this can have the opposite effect. Whispering is harder on a voice than speaking in a normal tone and therefore more likely to cause damage to your pipes.