Roosters almost always start crowing before four months of age. The rooster is often portrayed as crowing at the break of dawn, however, while many roosters crow shortly after waking up, this idea is not exactly true. A rooster can and will crow at any time of the day. Some roosters are especially vociferous, crowing almost constantly, while others only crow a few times a day. These differences are dependent both upon the rooster’s breed and individual personality. A rooster can often be seen sitting on fence posts or other objects, where he crows to proclaim his territory.
Roosters can be very loud. If a Rooster was standing right next to your ear it could produce a sound over 140 decibels, that is loud enough to cause some ear damage, and very close to shattering your ear drum.
Loud sounds (above 120 decibels) can cause permanent hearing losses because the intense air pressure waves can damage and even kill the cells that translate sounds into neurological signals. At more than 130 decibels, it takes less than a second to inflict lasting damage.
Fortunately for roosters, mother nature have provided them with their own “ear plugs”, they have special ears which allow them to crow as much and as loud as they want without losing their hearing. When roosters open their beaks fully, their external auditory canals completely close off.