SlapMac is a macOS application designed to generate auditory feedback in response to physical impacts or vibrations applied to a compatible MacBook. The core methodology of SlapMac centers on the real-time acquisition and processing of motion sensor data to detect discrete physical events, specifically "slaps."

The application leverages the integrated Inertial Measurement Unit (IMU), primarily the accelerometer, present in M1PRO+ MacBook models. This sensor continuously measures the instantaneous acceleration of the device in units of gravitational force ($g$). Upon a physical "slap," the accelerometer registers a sudden, significant change in acceleration, manifesting as a transient high-amplitude peak in the sensor data.

SlapMac processes this raw acceleration data to identify these impact events. The "force" of the slap is quantified by the magnitude of the detected acceleration peak. A configurable "Sensitivity" parameter acts as a threshold, determining the minimum acceleration magnitude required to trigger a response. This sensitivity can be finely tuned, ranging from extremely low thresholds (e.g., $0.051g$) to higher values requiring substantial impact.

Once an impact exceeding the set sensitivity threshold is detected, the application performs the following actions:

1. Volume Scaling: The detected peak acceleration ($A_{peak}$) is mapped to an output volume level ($V$). This is typically achieved through a function $V = f(A_{peak})$, where $f$ could be linear, logarithmic, or another non-linear mapping, ensuring that a "gentle tap" results in a whisper while a "full slap" produces maximum volume.
2. Sound Playback: A pre-selected sound clip from one of the application's seven voice packs (containing over 130 clips) is played at the calculated volume. Voice packs include themes like "sexy," "commentator," and "goat," among others.
3. Cooldown Mechanism: A "Cooldown timer" (e.g., 1.0s) is implemented to prevent rapid-fire triggering from a single prolonged vibration or very close successive impacts, ensuring distinct responses and preventing audio "meltdowns."

Beyond the primary slap-detection mechanism, SlapMac includes a "USB Moaner" mode. This feature operates by monitoring USB device plug-and-unplug events via the macOS system, triggering specific sound clips without requiring physical impact.

The application operates silently in the menu bar, with no dock icon, and can be configured to launch at login. It maintains a lifetime "Slap counter." Future developments include custom sound pack support (v1.2), allowing users to add their own audio, and integration with local Message Control Protocol (MCP) servers (v1.3) for programmatic control. A mobile counterpart, "SlapPhone," is also planned for iOS devices.