Why is the rooster not deaf by its own crowing?

According to the Zoology magazine, it may be loud enough to make a person walk too close.

Such sound intensity requires the hearing organ of the rooster to have a protective mechanism .

Scientists are interested in how they avoid consequences related to their loud crowing. Researchers at Belgian universities, including Antwerp, Brussels and Ghent, began their research with the measurement of the intensity of the crowing of roosters. They arranged the sensors at the top of the rooster's outer ear canal and found that the average sound pressure level was 130 decibels and in a particular rooster took part in the tests, Sound intensity even up to 142.3 decibels. This sound corresponds to the noise of jet aircraft flying at a distance of 25m and may have injured the inner ear of the person. At the same time, just stay away from the 1m drum, the intensity of the crow's neck has dropped to just 102 decibels.

Such sound intensity requires the hearing organ of the rooster to have a protective mechanism. Scientists have discovered that mechanism by using X-ray microcirculation of the rooster head layer. It turns out, when the rooster beaks out completely to make a crow, a quarter of the stethoscope of the chicken overlaps and the soft tissue closes nearly half the surface of the eardrum. This means that for roosters, the crowing of itself will be muffled.

Interestingly, in hens, when openings, the auditory canal only narrowed a bit, with no effect of closing the eardrum as in roosters.