Abstract: A computer-implemented method for redeeming an electronic coupon comprises receiving on a transmit device the electronic coupon that includes an embedded identifier that indexes coupon data; playing the identifier of the electronic coupon over air from a speaker of the transmit device in proximity to a receive device; decoding the identifier in response to the receive device receiving the audio signal over the air; and using the identifier to access the coupon data including purchase discount information.

Abstract: An acoustic dock for guiding placement and orientation of a mobile device for enhanced acoustic data transfer comprises a bottom surface; a plurality of sides attached to the bottom surface for receiving a mobile device having a transducer; and one or more transducers placed in proximity to at least one of the plurality of sides, where the acoustic dock is configured to assist orientation of the mobile device in the acoustic dock so that the mobile device transducer is adjacent to and in proximity to the one or more transducers of the acoustic dock to facilitate acoustic data communication.