It shall be unlawful for any person to operate a motor vehicle, bicycle, electric personal assistive mobility device, electric power-assisted bicycle, or moped on the highways in the Commonwealth while using earphones on or in both ears. For the purpose of this section, “earphones” shall mean any device worn on or in both ears that converts electrical energy to sound waves or which impairs or hinders the person’s ability to hear, but shall not include (i) any prosthetic device that aids the hard of hearing, (ii) earphones installed in helmets worn by motorcycle operators and riders and used as part of a communications system, or (iii) nonprosthetic, closed-ear, open-back, electronic noise-cancellation devices designed and used to enhance the hearing ability of persons who operate vehicles in high-noise environments, provided any such device is being worn by the operator of a vehicle with a gross vehicle weight rating of 26,000 pounds or more. The provisions of this section shall not apply to the driver of any emergency vehicle as defined in § 46.2-920.