arrival chime; arrival sound
Refers to the chime or announcement sound played when an elevator, train, or similar vehicle arrives at a stop or floor.
エレベーターの到着音が鳴った。
The elevator's arrival chime sounded.
駅のホームで電車の到着音を聞いた。
I heard the train's arrival sound on the station platform.
Compound of 到着 (arrival) and 音 (sound). The exact origin is uncertain, but it likely emerged with the spread of automated announcement systems in elevators and trains.