Overall this bell seems like the wrong solution, and it took me a while to realize not every country has outlawed headphone wearing for bicyclists, something I guess I took for granted.
It doesn't make sense for a car driven to use headphones, so not sure why it'd make sense for other vehicle-users to use them either, as you say, we really do use our ears to help navigate traffic so allowing people to be so careless seems... Careless?