There is the "European" siren (Martinshorn in German) which is just two tones (typically a' followed by d'') and sounds like [1]. There is also a slightly higher pitched version used by vehicles stationed inside cities.

It's still loud, but subjectively less stress inducing and objectively easier to locate. The most obvious feature is that you can very easily tell if the emergency vehicle is moving towards you or away from you as well as the approximate relative speed because the doppler shift is really easy to pick up by ear.

1: https://freesound.org/people/DominikBraun/sounds/459880/