Method and mobile apparatus for providing alternative audio during combined rendering of video and audio content (a film for instance), the method comprising: Receiving via a microphone of the mobile the audio signal associated with the rendered combined audio and video content; analysing the acoustic audio signal to extract a watermark or fingerprint to determine a current playback position of the combined video and audio content; synchronising an alternative audio with the determined current playback position. Concurrently playing the alternative audio synchronised at the current playback position.