Detection method of mobile terminal spatial location using audio watermark technique

We have been developing audio watermarking techniques which enable extraction of embedded data by cell phones. Applying an auditory stream segregation, we could embed data onto full phone-line frequency ranges, where our auditory response is prominent, with suppressing playback audible noises in order to make possible to extract data with a 3-G mobile phone. Applying this technique, we are developing a mobile terminal location detection method against multiple sound sources with unique codes embedded. In this paper, we propose an improved method, which enables to extract five different codes depending on the extracting microphone location between two-channel stereo loudspeakers, by embedding two different codes to each channel of stereo signals.