While some acoustic studies discover that the utterance F0 of male and female speakers, irrespective of physiology, differs, others disagree with this assertion. Various perception studies addressing the issue reveal that female speech tends to exhibit greater pitch fluctuations and melodic intonation compared to their male counterparts. Therefore, this issue remains controversial. Moreover, situational contexts are known to interact with F0 in utterances, introducing complexity to its investigation. To bridge gaps in previous research that failed to quantifiably discern acoustic disparities in male and female F0 during speech, this study aims to investigate pitch differentials regardless of physiological factors within diverse situational contexts.

            Data were collected from three male and three female native Thai speakers aged 20-22 years. Thai sentences were elicited through both scripted and spontaneous speech. Employing pitch dynamism, a two-dimensional measure (x, y) combining pitch perturbation (rate and directionality of F0 change, obtained by calculating the slope of the linear equation y = ax + b by tracing a trendline across an utterance's F0 plot, where F0 is measured at every 1 millisecond) and pitch variance (F0 distribution in a specific utterance, obtained by calculating the standard deviation from F0 measurements). The results demonstrate that gender-related differences do indeed exist in the modulation of F0 during speech among Thai speakers. Notably, female speakers display greater F0 fluctuation, particularly in terms of pitch variance, in contrast to their male counterparts. Furthermore, situational factors, especially question and negation contexts, influence F0 variability. Statistical analyses reinforce the significance of gender-specific patterns within distinct contexts.

            In conclusion, this study affirms the presence of F0 variations between Thai male and female speakers beyond physiological distinctions. Additionally, situational context also contributes significantly to shaping F0 variations and gender-related differences in speech patterns.