Shulou(Shulou.com)11/24 Report--

Cluck, cluck, cluck!

My eyes are disturbed. | how noisy is the crowing of Giphy chickens? Measured in decibels, it's about as noisy as a big truck speeding past you or someone operating a lawnmower in your ear.

Someone measured the rooster's crowing at a distance of 1 meter and found that the sound level reached 100,126 decibels. You know, the sound of a chainsaw is about 120 decibels. It's like a chainsaw causing devastating damage to our tympanic membrane and brain in the early morning when we are woken up by a chicken crow.

At random, there are a lot of victims awakened by the crowing of chickens.

You know, just like listening to chainsaws for a long time, hearing will be impaired if you listen to chickens crowing for a long time.

Sometimes we stay in a noisy environment for a while, only to hear a deeper voice in the next few days. This is a temporary hearing threshold shift (temporary threshold shifts), and the ear will adopt some self-protective mechanisms in the noise. However, when the sound is louder and lasts longer, the ear's self-regulating mechanism does not work, causing more severe hearing loss.

Prolonged exposure to noise of more than 70 decibels may damage hearing, and noise of more than 120 decibels may cause immediate ear damage.

Be safe and stay away from the noise! | Giphy researchers put a microphone in the mouth of a chicken's ear to measure the sound volume transmitted to the chicken's ear. Of course, in order to withstand the "chainsaw volume" of a chicken, the microphone is powerful enough to measure sounds of more than 140 decibels. Sure enough, it was found that when the rooster crowed, the sound in the chicken's ear was as high as 130 decibels.

The microphone is on! | reference [1] since sound can cause direct hearing loss to both humans and birds, why don't chickens make themselves deaf when they crow so loudly?

It has been found that the magical protective mechanism appears in the chicken's own ears.

Researcher CT scanned the ear structure of a rooster when it opened its mouth and analyzed it. It was found that when the rooster crowed, that is, when the mouth was opened to the maximum, the external auditory canal would be closed. It's like wearing an earplug.

The structure of the ear canal of a rooster is shown in figure A (before crowing) and figure B (during crowing). The hen is shown in figure C, D | reference [1] at the same time, when the chicken's beak is at its maximum, the soft tissue in the ear canal is directly covered with 50% of the tympanic membrane. In other words, the earplugs are tighter and thicker. In addition, the rooster crowing will also affect the hearing bone-related muscles, can also achieve a noise reduction effect of 10 to 20 decibels.

In other words, even if the rooster cackles continuously for an hour, he himself is as quiet as wearing noise reduction headphones, and maybe even more noisy.

You can't hear the hustle and bustle of the outside world at all, but the hen may be deafened by the rooster, because the study found that the hen shrinks the diameter of the external auditory canal less than the rooster because of some structural differences in the mandibular muscle. after all, the sound of the hen is already lower, only about 70 decibels.

It seems that the hen can only stay away from the rooster if she wants to protect her ears. Maybe we want to protect our ears for the same reason.

Run! run! The rooster is going to crow! | Pixabay not only chickens learn the noisy trick of self-protection, but also cicadas. Cicadas sound like thunder in some areas in summer, and as the loudest insects, they will not be deafened by themselves. Cicadas have ears and auditory receptors. When they hear the sound, cicadas contract their abdominal muscles, causing the tympanic membrane on their abdomen to contract to produce nerve pulses. Can't they hear the sound of their own child?

As a matter of fact, I can't hear you. After measurement, one of the most sensitive sounds of male cicadas is 2.1kHz, but the frequency of its shouting is 4.5kHz, and its tympanic membrane is not sensitive to the frequency of its shouting, and it sounds less harsh.

Cicadas will not be deafened by themselves. | Pixabay people have found that, like chickens, they also have a self-protective mechanism. When the male cicada cries, its tendons contract and the auditory membrane wrinkles, reducing its sensitivity to sound.

Female cicadas are also victims. In terms of the sensitivity of the tympanic membrane to sound, they are also sensitive to the sound frequency of male cicadas. But this is also easy to understand, after all, the male cicada shouting itself is to find a partner.

When a rooster crows, he is actually declaring sovereignty. It has been reported that when crowing, chickens do not bark casually, but in a certain order: the rooster of high status barks first, and then those of low status crow in turn, and the order of crowing needs to be strictly observed.

Because crowing also means "this land and the hen are mine!"

Cover source: Pixabay

Reference:

[1] Claes, Raf, et al. "Do high sound pressure levels of crowing in roosters necessitate passive mechanisms for protection against self-vocalization?." Zoology 126 (2018): 65-70.

[2] Sueur, J é r ô me, James FC Windmill, and Daniel Robert. "Sexual dimorphism in auditory mechanics: tympanal vibrations of Cicada orni." Journal of Experimental Biology 211.15 (2008): 2379-2387

[3] https://phys.org/news/2015-07-cock-roosters-crow.html

This article is from the official Wechat account: bring Science Home (ID:steamforkids), written by: Skin, revised by Proxima Star

Welcome to subscribe "Shulou Technology Information " to get latest news, interesting things and hot topics in the IT industry, and controls the hottest and latest Internet news, technology news and IT industry trends.