Characterizing the subjective performance of the ITU-T 8 kb/s speech coding algorithm-ITU-T G.729

Three listening-only experiments were conducted to characterize the subjective performance (i.e., speech quality) of 8 kb/s G.729. These experiments evaluated the quality of coded speech under a variety of conditions: (i) interworking with other international and regional speech coding standards; (ii) input speech that had been corrupted by environmental noise; (iii) operation over degraded transmission channels (including random bit errors and a simulated radio channel). The results of these experiments indicate that 8 kb/s G.729 meets the performance requirements that were established at the beginning of the standardization process.