Brian Moore's Busy Simulator enables you to play the notification sounds of Slack, iMessage, Outlook, Discord, and other apps so that you sound busy, to your co-workers or perhaps just to yourself. Turning them all on creates a very unnerving app symphony that captures the zeitgeist. Try it here!
From the instructions:
Use the sliders to increase the speed of the insanity or whatever.
Tip: turn "Original Sound" to On on Zoom for best effect.