If you've ever heard the sound of a rooster crowing early in the morning, it's not something you'll soon forget. Hearing that loud noise is likely to be effective as a wake-up call, though probably not appreciated. The piercing sound can even be painful if you’re in close proximity to it. In fact, a rooster can crow at over 130 decibels, which is just shy of being able to shatter a person’s eardrum. How is it, then, that roosters don’t have permanent ear damage themselves?
Researchers have discovered that when a rooster crows, its external auditory canals close off, thus giving it built-in earplugs, so to speak. And unlike humans, birds have the ability to regrow hair cells in the inner ear if they become damaged. For us, hearing loss is permanent, but for the rooster, it's temporary. Loud sounds, then, are not an issue for them.
If a rooster’s crowing seems to increase in volume, evidence suggests that it could be a means of telling other roosters to stay away from his hens. Of course, the intensity of a rooster’s crow diminishes with distance. While roosters themselves aren’t capable of hearing their crows at full volume, others around them aren’t so lucky.
Cock-a-doodle-doo!
- An average rooster call measures over 130 decibels, which is comparable to the sound intensity of a jet taking off at a distance of 15 meters (49.2 feet) away.
- Hen calls are significantly quieter than rooster calls, clocking in at only 70 decibels.
- Researchers from the University of Antwerp and the University of Ghent in Belgium attached microphones to three rooster heads in an attempt to measure the sound levels roosters experience when they crow. They then created micro-CT scans to get an idea of the geometry of their ear canals when their beaks opened and closed.