Voice preference, unlike other areas of human voice research, has been relatively underexplored, despite being a major category in voice evaluation. Current studies on voice preference have not yet leveraged music harmony theory, which provides a clear standard for sounds that are generally considered pleasant. In this study, I investigated the relationship between the harmonic structure of voices and their perceived preferences. Ten voice samples in Korean were evaluated for preference using the Mean Opinion Score (MOS) method, and the results were compared to voice harmony analyses through two approaches: the cent method and the weight method. The results demonstrated that voices with higher preference ratings tended to align more closely with musical harmony, offering a novel approach to understanding voice likability. These findings could have broad implications for fields such as voice synthesis and human-computer interaction.

Voice likability is a critical factor in machine-human interaction. However, studies on speech likability typically does not apply the harmony theory in music, which suggests general rules for pleasant sounds. In this paper, I propose a new method that estimates the likability of vocal signals using the harmonic relation of pitch and the first formant (F1). I extract the pitch and F1 from the vowel signal and compute the average cent value between notes in the musical scale from each pitch and F1. A small cent value indicates a consonant relation between pitch and F1. I compared the calculated cent values with the MOS test results from ten speech samples. The results showed a clear correlation between the subjective MOS scores and the consonance of pitch and F1 in vowels.