KyotoMOS: An Automatic MOS Scoring System for Speech Synthesis

The Mean Opinion Score (MOS) serves as a subjective measure for assessing the quality of synthesized speech. Nevertheless, the conventional approach to MOS evaluations can be resource-intensive in terms of both time and cost. This article unveils an automatic MOS scoring toolkit that builds upon our success in securing the top position for some metrics in VoiceMos2022 Challenge and emerging as champions in some tracks of the VoiceMos2023 Challenge. We offer a pre-trained MOS scoring tool for English and provide training code for other languages. Our documentation, examples, and source code are available at https://github.com/superphysics/KyotoMOS.