One-bit audio is sound generation with only two signal states, typically on and off. Instead of playing a full digital waveform, software rapidly switches a speaker, beeper, or other output so that the timing of those pulses creates audible tones, rhythms, or effects. This is a very low-fidelity technique, but it can still produce useful or distinctive sound when the timing is precise.
In cybersecurity, one-bit audio matters because simple hardware outputs can be abused as covert channels, proof-of-concept payloads, or distraction mechanisms. Malware or testing tools may use a beep device to signal status, leak small amounts of information, or interact with systems that expose little else. Defenders should notice unexpected access to audio hardware, unusual pulse patterns, or code that toggles output pins at high frequency. The same constraint that makes one-bit audio primitive also makes it easy to overlook.