Comparison of transmission quality dimensions of narrowband, wideband, and super-wideband speech channels

It is commonly acknowledged that the introduction of wideband and super-wideband speech transmission in Voice-over-IP leads to an improved overall quality compared to traditional narrowband telephony. However, beyond overall quality, dimensions such as coloration, continuity, noisiness, loudness, human speaker identification ability, as well as automatic speech and speaker identification performance may benefit from the augmented speech transmission bandwidth. In this paper, we review data on all of these quality and performance dimensions and classify them along a recommended “transmission rating scale” into eight service quality classes which are useful for transmission network planning. Applications of the results are discussed for different human-to-human and human-machine application scenarios.