Disappointed that the article does not mention the very distinct retro-tech drone of the inverter-based power supply of the Soviet Metrovagonmash 81-814 and 81-

Disappointed that the article does not mention the very distinct retro-tech drone of the inverter-based power supply of the Soviet Metrovagonmash 81-814 and 81-817 trains (1,2). Also interesting to note that the Montreal Metro sound lives on as the low-speed pedestrian awareness sound of the electric LionC school bus, which are manufactured in Quebec. (1) https://m.youtube.com/watch?v=jVGEPiyJync https://m.youtube.com/watch?v=jVGEPiyJync (2) https://m.youtube.com/watch?v=ztcEP8jWOfM https://m.youtube.com/watch?v=ztcEP8jWOfM