Concurrent data transmission on analog telephone channel by data hiding technique

In this paper', a hijden channel created by removing the audio coinponents below a percepiiiul musk is pi-oposed to transmit e,rtra data cunciiri%'nt!v with voice iliroiigh a ielephone channel. While a conventional phone ferminal is still able to access the hasic voice service, the udded decoding inechani.~in can extract the hidden data and pi~ovide man)> concurrent services, snch as non-in~ermption cull waiting arid conciirrent text messages. The e.rperimenta1 resdts show /ha! on acceptahle data rate can be uchieved by the proposed scheme. service. Index Terms Data hiding, PSTN, speech coding, concurrent