WASHINGTON — Ever since automakers began recalling millions of vehicles with defective airbags made by the Takata Corporation in 2008, the company has remained largely silent in the United States.

On Thursday, that silence ended when a senior Takata executive testified during a Senate hearing that was called to examine a defect in the company’s airbags, which can explode violently when they deploy, sending metal debris flying into the car’s cabin. At least five deaths and dozens of injuries have been linked to the problem.