Engineering360: "The Friendly Car Horn"

Worthy research; relevant for the new breed of ultra-quiet hybrid and electric cars where driving silently in streets with many pedestrians creates new hazards.

Many years ago I was enchanted by the "horns" used on Spanish Metro trains - loud, but warm, husky tones as though from a wooden pan flute. Effective but pleasant on the ear. Why can't most alarms be more pleasant? Surely a microwave oven could have a more inviting sound to let you know your food has been heated than a PING!