When I was driving I always tended to have my window open to some degree, since I preferred a steady stream of fresh air.
I may be the exception.
Many folks would rather drive around with windows all the way up, relying on AC systems.
This group could benefit from a low level vibration from sirens. Also, many of today’s E-Cars are virtually silent, not giving much warning to their approach. Some of the emergency vehicles may also be electric and thus, muted.
I’m really hearing impaired and unfortunately sirens tend to be in the frequencies where I’m most impaired
Low frequencies are much more noticeable.
This would sure help me not nearly jump out of my skin at last second.
😊