Embodiments of the invention present a system and method for controlling audio capture by a smart pen based computing system. An audio capture mechanism that is independent from a gesture capture system is included on the smart pen to control audio capture by one or more microphones included on the smart pen. In one embodiment, the audio capture mechanism comprises a shared function button, such as a power button. For example, a user interaction with the shared function button initiates audio capture by the one or more microphones on the smart pen and a second user interaction with the shared audio function stops audio capture. Alternatively, audio capture is stopped after completion of a predefined time interval after the user interaction with the shared function button.