scope:

The objective speech quality estimated by the Auditory Non-Intrusive QUality Estimation Plus (ANIQUE+) model of this American National Standard (ANS) is the subjective quality of telephone band speech.

The quality estimated or predicted by the ANIQUE+ model is not conversational quality but listeningonly quality, which can be originally obtained by subjective auditory tests investigating listening quality in Absolute Category Rating (ACR) scale using a common receiving handset at a standard listening level of 79 dB SPL (See ITU-T P.800 and P.830). This ANS can be used to predict the quality of one-way speech transmission.

Purpose

The need for objective models for estimating speech quality is becoming more prominent, especially in complex modern telecommunication network environments. In addition to existing traditional public switched telephone networks (PSTN), various types of mobile and internet-based networks are being widely used. The resulting interconnected heterogeneous network increases significantly the number of factors that can affect speech quality, and the understanding of the impact of individual system components and combinations of them on the end-to-end speech quality is very difficult. In addition, these newer networks provide a tradeoff between service quality and cost. Thus, the reliable estimation of speech quality over modern telecommunication networks is very important not only for network systems design and development, but also for the maintenance of quality of service (QoS).

This ANS defines an algorithm which provides acceptable accuracy in estimating the quality of speech processed by telecommunication networks in a non-intrusive manner. For 20 Mean Opinion Scope (MOS) test databases which have never been used in the development of objective models, the average correlation between subjective and objective quality scores is about 0.87 for this ANS, whereas the ITUT P.563 shows about 0.81 correlation for the same task.