@uliwitness @storiesofapple On the #Mac you can find this in the #macOS Control Center in your menu bar. You can even have a special menu item appear when something is playing: https://support.apple.com/guide/mac-help/change-control-center-settings-mchlad96d366/mac
#SoundSource by @RogueAmoeba goes further by optionally displaying app-specific mute-able volume meters in the menu bar, as well as controlling per-app volume, effects, and audio output destinations: https://RogueAmoeba.com/support/manuals/soundsource/?page=menubarcontrols#details-on-menu-bar-meters
Modern enough for you?
@mjgardner @uliwitness @storiesofapple SoundSource definitely aims to help with this issue! In addition to menu bar meters, you can also just pop open SoundSource’s main window. The Applications section will show any app that’s produced audio in the past 15 seconds.
We’re looking at how we can make this even more clear in the future.