Roosters are known for their loud crowing, but what contributes to a rooster’s soundproofing so it doesn’t go deaf from its own noise?
Researchers from the University of Antwerp and the University of Ghent dove into this mystery, revealing some surprising adaptations that protect these birds from self-induced hearing loss.
Crowing Loudness: More Than Just a Wake-Up Call
The research team embarked on a mission to determine the actual loudness of a rooster’s crow. They equipped sample roosters with tiny microphones near their ears to measure the intensity of the sound. Astonishingly, they discovered that the crowing averages over 100 decibels.
To put this in perspective, that’s comparable to the noise produced by a running chainsaw.
Continuous exposure to such noise levels typically leads to deafness in humans, caused by irreversible damage to the tiny hair cells in the inner ear. Since chickens, including roosters, possess similar hair cells, the team was curious about why these birds don’t suffer hearing damage.
A Built-In Ear-Plug Mechanism for the Rooster’s Soundproofing
The key to this avian riddle lies in the rooster’s unique anatomical structure. Through micro-computerized tomography scans of the birds’ skulls, the researchers uncovered two crucial adaptations.
First, they found that a portion of the rooster’s eardrum is covered by soft tissue, significantly dampening incoming noise. More impressively, when a rooster throws its head back to crow, another piece of material acts as a natural ear-plug, covering the ear canal completely.
This ingenious mechanism functions much like a person blocking their ears to muffle sound, providing the rooster with a form of self-protection against its own deafening calls.
Another intriguing aspect of avian biology plays a role here. Unlike humans, birds possess the ability to regenerate damaged hair cells in their ears. This regenerative capability provides an additional layer of defense against potential hearing damage.
But what about the hens and chicks that are within earshot of the male’s powerful crowing? While not explicitly covered in the research, it’s commonly observed that roosters often choose elevated and distant spots for crowing. This behavior ensures maximum sound reach while maintaining a safe distance from the hens and chicks, thereby reducing their exposure to harmful noise levels.