Abstract: A system for supplementing an audio signal with auxiliary data in an inaudible channel. The system can include an audible radio signal source having at least a left channel and a right channel. A digital signal processor can be programmed to transform the audible radio signal source into a frequency domain representation having multiple frequency component portions of the audible radio signal. A comparator can be coupled to the digital signal processor and can have an established imperceptible IPD. The comparator can identify selected ones of the frequency component portions having corresponding phase values which do not exceed the imperceptible IPD. Finally, an encoder can be configured to encode a digital auxiliary data signal into the audible radio signal by modifying the corresponding phase values to correspond to individual bit values of the digital auxiliary data.

Abstract: A method is provided for embedding data into an audio signal and determining data embedded into an audio signal. In the method for embedding data into an audio signal, the audio signal is based on a first set of data and includes a phase component. The method modifies at least a portion of the phase component of the audio signal to embed a second set of data into the audio signal. The modified audio signal can be made to differ with respect to the audio signal in a manner at least one of (i) substantially imperceptible and (ii) imperceptible to a listener of the first set of data depending on the extent that the phase component of the audio signal is modified. In the method for determining data embedded into an audio signal, the audio signal is based on a first set of data of an original audio signal and includes a phase component. The method determines a second set of data embedded into the audio signal based on the phase component of the audio signal.

Abstract: A system for supplementing an audio signal with auxiliary data in an inaudible channel. The system can include an audible radio signal source having at least a left channel and a right channel. A digital signal processor can be programmed to transform the audible radio signal source into a frequency domain representation having multiple frequency component portions of the audible radio signal. A comparator can be coupled to the digital signal processor and can have an established imperceptible IPD. The comparator can identify selected ones of the frequency component portions having corresponding phase values which do not exceed the imperceptible IPD. Finally, an encoder can be configured to encode a digital auxiliary data signal into the audible radio signal by modifying the corresponding phase values to correspond to individual bit values of the digital auxiliary data.