Speech Bandwidth Extension Aided by Hybrid Model Transform Domain Data Hiding

Public telephone systems are limited to narrowband (NB) frequency range of 300–3400Hz, which affects the quality and intelligibility of telephony speech. In this paper, a new Hybrid Model Transform Domain Speech Bandwidth Extension (HMTDBWE) algorithm is proposed to transmit the missing speech frequencies of wideband (WB) speech over a steganographic channel. The proposed Discrete Wavelet Transform-Fast Fourier Transform-Based Data Hiding (DWTFFTBDH) technique is developed to incorporate the hidden spectral envelope parameters within the narrowband speech signal and transmitted over the channel. This hidden information is recovered reliably at the receiver side to produce a reconstructed wideband telephony speech of much higher quality. The simulation results of the proposed method show improved speech quality over the other data hiding methods.