This research proposes an enhanced measurement method for VoIP quality assessment which provides an improvement to accuracy and reliability. To improve the objective measurement tool called the simplified E-model for the selected codec, G.729, it has been enhanced by utilizing a subjective MOS prediction model based on native Thai users, who use the Thai-tonal language. Then, the different results from the simplified E-model and subjective MOS prediction model were used to create the Bias function, before adding to the simplified E-model. Finally, it has been found that the outputs from the enhanced simplified E-model for the G.729 codec shows better accuracy when compared to the original simplified E-model, specially, after the enhanced model has been evaluated with 4 test sets. The major contribution of this enhancement is that errors are reduced by 58.87 % when compared to the generic simplified E-model. That means the enhanced simplified E-model as proposed in this study can provide improvement beyond the original simplified one significantly.

翻译：本研究提出了一种增强型VoIP质量评估方法，在准确性和可靠性方面实现了改进。为优化针对选定编码器G.729的客观评估工具——简化E模型，通过基于以泰语调性语言为母语的泰国用户的主观MOS预测模型对该模型进行了增强。随后，利用简化E模型与主观MOS预测模型的差异结果构建偏差函数，并将其叠加至简化E模型。最终发现，经增强后的G.729编码器简化E模型输出结果较原始简化E模型具有更高准确性，尤其在通过4组测试集验证后效果显著。该增强方法的核心贡献在于：与通用简化E模型相比，误差降低了58.87%。这表明本研究所提出的增强简化E模型可较原始模型实现显著性能提升。