As the brake pads wear down over time, the wear indicators make contact with the brake rotor or drum, creating an audible squealing or scraping noise. This noise serves as a warning signal to the driver that the brake pads are nearing the end of their lifespan and should be inspected and replaced to ensure optimal braking performance and safety. Monitoring and responding to wear indicators promptly can help prevent brake pad damage, rotor wear, and potential brake failure.