What type of inserts are categorized as ear plugs?

Foam or rubber inserts are categorized as ear plugs because they are specifically designed to fit comfortably in the ear canal, effectively reducing the volume of sound that reaches the eardrum. These materials are soft and moldable, which allows them to conform to the shape of the ear, providing better noise isolation and a secure fit. Foam ear plugs expand once inserted, creating a seal that helps protect hearing in noisy environments. Similarly, rubber inserts also provide effective sound dampening and can be reused, making them a practical choice for various activities that require hearing protection.

While metal inserts, silicone protectors, and plastic molds have their applications, they do not serve the primary function of ear plugs as effectively. Metal inserts would typically not be used for hearing protection due to their rigid nature, while silicone protectors are often designed for comfort but may not always provide the same level of sound attenuation as foam or rubber. Plastic molds can be formed for custom fit but are generally less common as everyday ear plugs compared to foam or rubber options.