Artificial Bandwidth Extension of Telephony Speech by Data Hiding

Speech Bandwidth Extension Using DWT-FFT-Based Data Hiding

“…The subjective listening tests were made on one hundred speech utterances drawn randomly from the two hundred forty speech utterances. Here, the perceptual transparency (PET) is evaluated using a mean opinion score (MOS) test [8], [9]. The listening test for the comparison of the WB, CNB and RWB signals is conducted [12].…”

“…The performance of the proposed BE algorithm is assessed with subjective and objective tests. The different methods compared with the proposed method are: BE of telephony speech by data hiding [8], speech BE by data hiding and phonetic classification [9], an audio watermark-based speech BE [10] and steganographic WB telephony using NB speech codecs [15]. These are represented, respectively, by conventional speech BE using data hiding (CSBUDH), conventional speech BE using data hiding and phonetic classification (CSBUDHAPC), conventional speech BE using bit stream data hiding (CSBUBSDH) and conventional speech BE using watermark transmitted side information (CSBUWTSI) in the analysis.…”

“…Several state-of-the-art techniques for speech BE based on data hiding are available. A speech BE method has been proposed in [8], where the encoded spectral envelope parameters (SEPs) of the MSFs in 4 to 8 kHz range, called high-band (HIB) signal, are hidden into the NB signal to produce a composite NB (CNB) signal. A method for generating a high-quality WB signal over the above method has been proposed in [9], where HIB signal is encoded more efficiently by phonetic classification.…”

“…These algorithms should also be robust enough to withstand channel and quantization noises. However, many of the methods discussed above [8][9][10][11][12][13][14][15][16] fail to provide a high-quality CNB signal and RWB signal. Also, they fail to provide robustness to withstand channel and quantization noises.…”

“…The telephone network channel effects, such as quantization and channel noises, are incorporated in this paper. More elaborate proposals, such as [8] and [9], aiming at speech BE, account for the aspect of quantization noise. However, the impact of channel noise has not been evaluated.…”