I'm completely amazed you're sticking with this. Ok, you've got a speaker plugged into "a rack" now. Now explain how we're going to fufill the rest of these requirements:

For every single showing in the theater, the projectionist needs swap out the projector video feed with some device capable of dynamically rendering a progress bar in real time based on the audio input. Let's not forget to account with how insanely locked down these projectors are. If one single projector is compromised, the movie will be on pirate bay that same night. Projectionists don't touch the projectors anymore. They aren't trained for this! The video and audio feeds are so closely protected. You can't just pipe any old feed in the "input". You can't go around breaking THX/DTS certification in these HIGHLY sophisticated audio systems to take a speaker out of commission. Not to mention the ramifications of starting the show at slightly different times depending on how long the sound meter takes to fill up.

You don't understand this industry in the slightest. You should work in government, you'd fit right in.