I saw an interesting article at Controlgeek blog titled America’s Got Talent Buzzer Show Control. It tells how the judge buttons work in the “World’s Largest Talent Show”. Those buttons sound a loud buzzer sound effect, fire a bunch of strobes and light cues, and trigger video on large upstage video wall. Often on TV, things like this are done just with a bunch of backstage operators (lighting, sound, video, etc.) triggering their systems manually, and it gets close enough to look OK. This show is controlled by a laptop computer that is interconnected to audio system, lighting desk and video wall controlling. Read America’s Got Talent Buzzer Show Control article for more details.
Using a PC for this kind of application makes sense. I also used laptop PC based approach many years ago on TV show light system I built years ago for one small TV production. You can find details of my systems on my Scene Quiz Show lights article I posted to this blog few years ago. My system was connected to sound effects and light dimmer.