• P.Srinivasa Rao
• V.Sagar Reddy

The public switched telephone network (PSTN) systems are only able to deliver speech signals in a narrow frequency band about 300–3400 Hz. Such a bandwidth is so small that the intelligibility of speech suffers frequently poor subjective quality. Meanwhile, codes for Wide Band (WB) telephony (50Hz to 7 kHz) exist with significantly improved speech intelligibility and naturalness. However, the broad introduction of wideband speech coding will require strong efforts of both network operator and customers because many elements of the networks have to be modified that turns out to be time-consuming. In order to improve intelligibility and perceived quality of telephone speech, we propose data hiding method based on dither quantization is used for speech bandwidth extension. More specifically, the out-of-band information is encoded and embedded into the narrowband speech without degrading the quality of the band limited signal. At the receiver, when the out-of-band information is extracted from the hidden channel, it can be used to combine with the band limited signal, providing a signal with a wider bandwidth. To encode the out-of-band speech more efficiently. That the proposed approach is robust to quantization errors and channel noises. Al- though we cannot physically extend the transmission bandwidth of PSTN, the telephony speech quality can be significantly improved by using the proposed data hiding technique.

Speech bandwidth extension, Data hiding, public switched telephone network (PSTN), wideband speech coding.

"Bandwidth Extension of Speech using Data Hiding method", International Journal of Emerging Technologies and Innovative Research (www.jetir.org), ISSN:2349-5162, Vol.3, Issue 7, page no.48-50, July-2016, Available :http://www.jetir.org/papers/JETIR1607011.pdf

"Bandwidth Extension of Speech using Data Hiding method", International Journal of Emerging Technologies and Innovative Research (www.jetir.org | UGC and issn Approved), ISSN:2349-5162, Vol.3, Issue 7, page no. pp48-50, July-2016, Available at : http://www.jetir.org/papers/JETIR1607011.pdf