A method to merge data recorded using a wireless external multi-microphone system is described. The method includes determining a communication delay between a mobile device and an accessory device. In response to activation of a camera application, an activation indication is sent to the accessory device and, in response, the accessory device starts recording audio. In response to a camera event, a camera event indication is sent to the accessory device. The camera event includes starting a video recording, pausing/resuming a video recording, ending a video recording or taking a photograph. In response to receiving the camera event indication, the accessory device creates a marker corresponding to the reception time. The method also includes receiving, at the mobile device, the audio data and the marker; and merging image data and the audio based on the marker and the communication delay. Apparatus and computer readable media are also described.