By David Shepardson WASHINGTON (Reuters) -Electric car maker Tesla Inc is recalling 578,607 vehicles in the United States because pedestrians may not be able to hear a required warning sound of an approaching car due to loud music or other sounds played by its “Boombox” feature, a U.S. regulator said on Thursday. Tesla has issued 10 U.S. recalls over the last four months, including four in the last two weeks. The Texas-based company has come under increasing scrutiny from the National Highway Traffic Safety Administration (NHTSA). Tesla said it was not aware of any crashes, injuries or fatalit…