Some manufacturers have caught onto this type of psychological response. For example, they make baby rockers that rocks to the rhythm of a woman's steps as it simulates the sensations within the womb. Some even add a beating pulse, timed to the same rate of a woman's heart beat. Given that the first sound everyone hears is their mother's heart beating it's no surprise that to mimic the state of the womb will cause feelings of safety and relaxation.
If car alarm companies really wanted to make someone pay attention to their sirens they would make it sound like a woman shrieking.