What do bats and metal singers have in common? The Growl. For those unfamiliar with the term, growl is a common vocal technique in heavy metal, where one tries to create as hoarse and guttural a sound as possible. There are many types, such as the scream or the grunt, and it seems that bats know how to do it very well.
While they emit ultrasonic sounds to echo-locate insects in the dark, these creatures use thick structures in the larynx to communicate with each other at low frequencies.
“We have identified for the first time which physical structures within the larynx oscillate to produce their different vocalizations, using their so-called ‘false vocal folds’, as human death metal singers dosaid Coen Elemans, the study’s lead author and professor of biology at the University of Southern Denmark.
Insiders have observed of the individual larynxes dissected by bats with a microphone and placed under a microscope. Here two laryngeal structures responsible for the high and low extremes of a bat’s vocal range have been identified, covering three or four octaves more compared to the average human being.
Researchers found that high-frequency calls are produced in bats by thin membranes located over the vocal folds, while low-frequency calls came from the so-called false vocal cords; similar to the same “method” used by death metal singers for their vocals (such as that produced by AI).
It’s not entirely clear to researchers yet what these sounds actually mean, but we’re sure future research will uncover the secret. By the way, always remember that bats are not enemies, but our friends!
