Waaayy back our fire department trucks used to have mechanical sirens sounding like the NY one, and I think prior to that they had bells. Now they're all electronic hi-lo, though every service has it's own sequence. Police is simple hi-lo, fire department as well, but different intervals. Ambulance is something like hi-lo (long) and then a sequence of very short hi-lo sounds. Gas company, PoCo and municipial transportation have different signals as well.
The large stationary sirens (in case of severe emergency, or in rural areas to notify the volontary fire department) are still wailing mechanical sirens.
Our police cars have a single blue rotating light, only ambulances have the strobe bars. Pretty heavy here as well.
