Design and implementation of a parameter-based Voice Enhancement Device (VED) for Next-Generation Networking

Measurements show that the transmission delay in Next Generation Networking (NGN) typically exceeds the limit for acceptable voice quality. This paper presents the design and implementation of a parameter-based Voice Enhancement Device (VED) that operates on coded speech rather than on speech waveforms. This VED utilizes the information contained in speech parameters to achieve noise reduction and acoustic echo control. The approach needs no transcoding resulting in lower transmission delay, thus achieving acceptable voice quality in NGN. For objective test using ITU-T G.160, results show that the developed VED passed both the Acoustic Echo Control (AEC) and Noise Reduction (NR) tests. For subjective listening test, however, the NR section resulted in lower listening-effort Mean Opinion Score (MOS_LE). Nevertheless, increase in MOS_LE was achieved when the NR and AEC sections were combined to work together in the listening test.