What is Voice Quality

Speech quality is the most visible and important aspect of quality of service (QoS) for telecommunication networks. Hence, the ability to monitor and design for this quality has become a top priority. Speech quality refers to the clearness of a speaker’s voice as perceived by a listener. Speech quality measurement offers a means of adding the human end user’s perspective to traditional ways of performing network management evaluation of voice telephony services. Traditionally, measurement of users’ perception of speech quality has been performed by expensive and time-consuming subjective listening tests. Over the last three decades, numerous attempts have been made to supplement subjective tests with objective measurements based on algorithms that can be computerised and automated. This chapter describes the technicalities associated with speech quality measurement, and presents a review of current subjective and objective speech quality evaluation methods and standards in telecommunications.