DWT-DCT-Based Data Hiding for Speech Bandwidth Extension

Anotace: The limited narrowband frequency range, about 300-3400Hz, used in telephone network channels results in less intelligible and poor-quality telephony speech. To address this drawback, a novel robust speech bandwidth extension using Discrete Wavelet Transform- Discrete Cosine Transform Based Data Hiding (DWTDCTBDH) is proposed. In this technique, the missing speech information is embedded in the narrowband speech signal. The embedded missing speech information is recovered steadily at the receiver end to generate a wideband speech of considerably better quality. The robustness of the proposed method to quantization and channel noises is confirmed by the mean square error test. The enhancement in the quality of reconstructed wideband speech of the proposed method over conventional methods is reasserted by subjective listening and objective tests.