I'm pretty sure you'll get more than enough 90s, 80s or even earlier papers by searching "audio recognition", classification, etc... Also, having studied math

I'm pretty sure you'll get more than enough 90s, 80s or even earlier papers by searching "audio recognition", classification, etc... Also, having studied math in the university and knowing where to lookup things when needed is one thing but demonstrating the knowledge on the blackboard during the interviews is another, especially if you're a mid-career professional and don't have a time nor willingness to allocate month(s) for preparation.