A system configured to detect a tap event on a surface of a device only using microphone audio data. For example, instead of using a physical sensor to detect the tap event, the device may detect a tap event in proximity to a microphone based on a power level difference between two or more microphones. When a power ratio exceeds a threshold, the device may detect a tap event and perform an action. For example, the device may output an alarm and use a detected tap event as an input to delay or end the alarm. In some examples, the device may detect a tap event using a plurality of microphones. Additionally or alternatively, the device may distinguish between multiple tap events based on a location of the tap event, enabling the device to perform two separate actions depending on the location.