The contact owns a 2024 Audi Q4 E-Tron. The contact stated that while operating the vehicle in drive and reverse, the audible sound to alert pedestrians that the vehicle was in motion was intermittently inaudible. The contact stated that the sound was inoperable while the vehicle was in reverse, creating a back over hazard for pedestrians. The cause of the failure was not yet determined. The local dealer and manufacturer were notified of the failure. The failure mileage was 1,100.