A general perceptual tool for evaluation of audio codecs

Subjective evaluation forms an important part of any research work, where the feedback and perception of general public or a trained set of specialists are mandatory. Many audio and video coding techniques have emerged to tackle the bandwidth problems imposed by the Internet with data compression schemes either with lossless or perceptually lossless quality. In order to evaluate the performance of these techniques a Mean Opinion Score (MOS) test has to be performed with wide variety of subjects. In this paper we present a MOS tool developed to evaluate the audio codecs both in controlled and uncontrolled listening environments. The technique is based on the international telecommunication union - radiocommunication sector (ITU-R) standard. This novel approach of performing distributed listening tests in uncontrolled environments will help researchers to collect substantial feedback and perform statistical analysis of an audio codec´s performance in an efficient manner particularly for Internet driven applications. Results of perceptual evaluation of 8 sample audio files of different varieties with an adaptive time-frequency transform (ATFT) audio codec indicates the ease, independency, and the effectiveness of performing MOS studies with the proposed technique.