wtf is holo?

Holo is an experimental macOS utility that turns the desk space around a MacBook into four tappable zones you can assign actions to. It listens through the Mac's built in microphone, analyzes short bursts of sound from a tap, works out locally which of the four zones the tap came from, and then runs whatever action you assigned to that zone. The four zones sit in a fixed layout: a rear and front zone on the left side of the laptop, and a rear and front zone on the right side. The project describes itself as a research prototype rather than a finished product. Its automated signal processing tests pass, but how accurately it actually recognizes taps still depends on the specific MacBook, desk, room, and laptop position being used, and the project asks that no accuracy claims be made without running its own 60 tap evaluation on that exact setup. Setting it up starts with a calibration process: you tell Holo about your desk and MacBook position, then tap each of the four zones ten times, spreading the taps around rather than hitting the same spot, while Holo rejects taps that are too weak, muffled, or too loud. After all 40 samples are collected, Holo checks how consistent each zone was and lets you redo any zone that came out weak before saving the profile. You can also record background sounds like talking, typing, or room noise as negative examples so Holo learns to ignore them. Once a profile is set up, each of the four zones can be assigned one action, such as showing a visual highlight only, playing a system sound, copying or speaking text, opening a website, running a Shortcut, opening an app or file, running a shell command, or taking a screenshot. Actions only fire when Holo is confident about a tap, taps it is unsure about, or that happen while you are calibrating or testing, do not trigger anything. Building Holo requires macOS 14 or later, Xcode, and a tool called XcodeGen to regenerate the Xcode project file, and it only works with the MacBook's own built in microphone rather than an external one.