Hear with your eyes.

While Callout runs, pick “Callout Headphones” (or Default) everywhere. That is your spare output with a new name: Callout reads the game's sound from it and plays it to your real headphones in mono. If you pick the raw headphones instead, the sound bypasses Callout and the strips stay dark.

In order: 1) Windows' own “Mono audio” toggle must be off (Settings > Accessibility > Audio); it squashes sound to mono before Callout can see left from right. 2) The game must run in borderless windowed mode, not exclusive fullscreen, which hides everything drawn over it. 3) The game must play into “Callout Headphones” or Default. 4) Callout must not be paused. 5) Raise the sensitivity slider and press the quiet-footsteps test sound: if the strip lights, the setup is fine and the game is just quiet.

In the normal mode, yes: Callout needs a spare output besides your headphones to read the game's sound from. Most desktops have one (speakers, or a monitor with audio). If yours has none, install the free VB-Cable virtual device; Callout picks it up automatically. It adds about 70 ms of delay, so a real spare output is better. Display-only mode needs no spare device at all.

For people who hear the game normally and just want the strips. Callout listens to your headphones' own output and changes nothing about your audio: no mono, no spare device, no device switching, no added delay.

With any game that plays stereo sound through Windows, which is nearly all of them, as long as the game runs in borderless windowed mode. Callout shows left and right only. Front and back cannot be told apart from a stereo mix, and Callout does not try.

Callout reads the sound Windows is already playing and draws its own click-through window over the game. It never opens the game process, never reads its memory, never sends input, and sends nothing over the network. That puts it in the same category as a volume mixer or a chat window on a second monitor. No anti-cheat vendor endorses third-party software, and we do not claim otherwise.

In the normal mode about 20 ms between the game and your headphones, roughly a single frame at 60 fps. Display-only mode adds none. Pro users can measure the actual number on the Audio page.

That is your spare output, renamed and muted while Callout runs so games play into it without anyone hearing it. Callout gives it its old name back and unmutes it when you exit or pause. If the app ever crashes, it repairs this on its next start.

While it runs, Callout keeps Windows' default output on “Callout Headphones” so games play into it. To use your headphones directly for a while, choose Pause in the tray menu; Callout then leaves your devices alone.

Colour by loudness (Pro) is on: a sound louder than a fixed level shifts the strip towards the loud colour, whatever your sensitivity setting. Footsteps stay the normal colour; nearby gunfire goes red. It measures loudness at your ears, not distance, and the level can be moved under Advanced on the Audio page.

Pro is a one-time purchase through the Microsoft Store: glow shape, width, position and height, colour, brightness, fade, colour by loudness, saved profiles, the advanced thresholds and the delay tool. Everything needed to make Callout work, including the sensitivity slider and monitor choice, is free. Refunds go through the Microsoft Store.

None. There is no account, no telemetry and no network use. Settings live in a file under your AppData folder, and a short log next to it stays on your PC.