Hearing is sharpest in childhood and gradually becomes less sensitive with advancing age.

The longer version

Children usually hear a wider range of pitches than adults, particularly at the high end. The inner ear contains hair cells arranged along a spiral, with different positions responding to different frequencies, and the cells handling the highest pitches sit where mechanical stress and metabolic wear accumulate most.

Those cells are not replaced in humans, so losses build up gradually across the decades. Exposure to very loud sound accelerates the process by damaging the delicate structures directly. Changes further along the pathway matter too: the brain becomes slower at separating speech from background noise, even when pure-tone detection is still reasonable. The result is a slow, uneven decline rather than a sudden one.

Where this entry sits

These facts look at how the human body works in ordinary moments, from breathing and blinking to balance and sleep. They focus on anatomy, senses, and small reactions that happen constantly without any conscious effort. The full list sits on the Human Body page, where every entry is listed in order.