I'm old enough to remember bells on fire trucks, police cars and ambulances.
They've gone, with sirens now in vogue.
Also, street-mounted fire alarms. Red painted, set on a pedestal and seemingly randomly distributed aroundn the streets. When I was a nipper, if we had ever wanted to use one, it was a 300 yard ( pre-metric!) dash down our street and around the corner for the nearest one. Then you hoped you had something which you could use to break the glass in order to press the button. The drill then was that you stayed at the alarm until the fire brigade arrived, to tell them exactly where the fire was.
I don't remember belled emergency vehicles, but I do remember a long-gone invention that most commercial trucks had, to do with hand signals.
Using the first Holden as a reference point, when the 48/215 (FX) was released, it had no electric turn indicator lights, nor did its successor, the FJ. For Holden, those didn't come until the FJ was superseded by the FE. For the 48/215 & the FJ, the indicator system could be bought as an accessory, though whether as an appproved Holden accessory I don't know. The most common brand was usually Foxton. And possibly not stop lights either, though the first Holdens certainly had one tail light.
Most other cars of the late 1940s and early 1950s didn't have indicators either, though some English cars had semaphory things that lit up but didn't flash, called trafficators, which popped up out of the B-pillar when the switch was flicked. Digressing massively from my original point, but there's a been-and-gone invention for you, trafficators
Virtually all trucks of this era - which while reasonably powerful - were by today's standards, very slow. And usually they didn't have indicators or stop lights, as we now know them, either.
What sufficed were two simple hand signals - the ancestor of what cyclists still use to this day.
Extending your arm straight out the window horizontally meant you intended to turn right.
Doing the same but bending your elbow to 90 degrees meant you intended to stop - or at least were braking, or slowing down to stop.
Turning left - well this is a RHD country, and like I said, trucks of 50+yrs ago were typically slow....
So..........to my point, many trucks - and I remember seeing these thingummies right through the 1960s on trucks - had this crude device fixed to the truck's bonnet (or just on the front, if it was a cab-over-engine job) which was basically a mechanical arm with a yellow painted hand on the end. The driver operated it with a lever, and the hand would point horizontal for a right turn, and vertical for a stop.
To my puzzlement, as an adult, I have never seen a restored truck, of any size, from that era, that has one of these devices preserved