Squeaking

Squeaking is a high-pitched sound produced by friction between two surfaces. This friction often occurs when two materials that are slightly sticky or have a high coefficient of friction are rubbed together. The sound is generated by a stick-slip phenomenon, where the surfaces repeatedly stick together and then break free, causing vibrations that produce the audible squeak.

Common sources of squeaking include rubber on smooth surfaces, such as shoes on a gym floor or a door seal against its frame. It can also occur with metal components, like brake pads against rotors, or even with wood, particularly when dry. The pitch and loudness of the squeak depend on the materials involved, the pressure applied, and the speed of movement.

Squeaking can be an indicator of wear or a need for lubrication. For example, a squeaking brake pad might signal that it needs to be replaced. In other cases, squeaking is simply an annoyance, such as the squeak of a child's swing set, which can often be resolved by applying lubricant to the moving parts. In some contexts, like in animal communication, squeaking is a deliberate vocalization used for signaling.