A rooster’s crow is so loud, it can deafen you if you stand too close. How then do roosters keep their hearing? To find out, a team of researchers attached recorders to the heads of three roosters, just below the base of their skulls. Crows lasted 1 to 2 seconds and averaged more than 130 decibels. The researchers then used a micro–computerized tomography scan to create a 3D x-ray image of the birds’ skulls. When a rooster’s beak is fully open (when crowing), a quarter of the ear canal completely closes and soft tissue covers 50% of the eardrum. This means roosters aren’t capable of hearing their own crows at full strength. Lucky them!
The study, Do high sound pressure levels of crowing in roosters necessitate passive mechanisms for protection against self-vocalization?, was published in the journal of Zoology.