Next challange: Place a camera in front of the bike that scans approaching pedestrians. Calculate their head position and trajectory. Use directional speakers and focused sound beams to focus the ~780Hz sound towards the head(s) of the pedestrian(s). Now that you are not bothering the environment as much, you can increase the volume as well.
I would love that but not so much for pedestrians as for cars that don't see me on my bike. Ideally, the "bell" would automatically honk at them very loudly when they get too close.
I carry air horn and stick. But I am pedestrian.
what
Sound beam aimed at person in the way.
Bell costs more than the bike is ok?