Telephony Speech Enhancement for Hearing-Impaired People

One of the limiting factors of performance of any communication system is bandwidth. In telephone systems, the operational frequency of voice ranges from 300 to 3400 Hz called Narrow Band (NB). This NB causes remarkable depreciation of speech in terms of quality and intelligibility, specifically for hearing-impaired people. Speech Bandwidth Extension (SBE) technique is used to increase the quality and intelligibility of NB signal. In SBE method, additional data about the lost speech frequency components is transmitted along with NB signal. A better quality Wide Band (WB) signal is reconstructed at the receiver end using the transmitted missing speech frequency components. This paper explores the ability of SBE to enhance the quality and intelligibility of NB signal for hearing-impaired people. The enhancement in the quality and intelligibility of NB speech for hearing-impaired people is reasserted by subjective listening and objective tests.