Birds here still mimic the 90s car alarm (You know the one that cycles between patterns every few seconds) even though I haven't heard that particular car alarm in at least a decade. How long will it take for birds to change that song?

I'm near a military base and I've never heard birds take on the bugle songs that come over loudspeakers (e.g. revelry, taps). I've also never heard birds sing the Ice Cream truck song. What makes some certain sounds so impressionable on birds?