[UPDATE] Voice changes across the menstrual cycle in response to masculinized and feminized man and woman

<b>Objective:</b> Research has demonstrated that men prefer women’s voices with higher pitch and that women’s voices recorded at high compared to low fertility phases of the menstrual cycle are rated as more attractive. These findings suggest that voice conveys information relevant to reproductive success. Because voice attractiveness is higher during the high fertility phase and voice pitch positively predicts attractiveness ratings, it has been hypothesised that cyclical changes in vocal attractiveness are driven by changes in voice pitch. However, attempts to detect acoustic changes have produced mixed results. With the higher degree of ecological validity achieved by including social context (simulated interactions with men and women) and by recording voice in the three phases of menstrual cycles, the present study addresses limitations of previous research. <b>Methods:</b> Forty-eight naturally cycling women were recorded during the menstrual, late follicular (high fertility), and luteal phases while leaving voice messages to masculinized and femininized man and woman. <b>Results:</b> No cycle-related changes in pitch and pitch variability for the recordings directed to masculinized and femininized man and woman were detected. By including relationship status as predictor in additional models, higher-order interaction effects showed that single and partnered women displayed opposite cycle-related pitch changes directed only to women, but not men. <b>Conclusion:</b> The cycle-related voice changes found in the present study do not support the hypothesis that cyclic pitch variations represent an adaptive mechanism for attracting partners. We discuss cyclic changes in voice pitch in relation to intrasexual competition by taking into an account that the present study is likely underpowered for adequate testing the complex higher-order interactions.

研究目的：既往研究证实，男性更偏好音调偏高的女性嗓音；且相较于月经周期低生育力阶段录制的样本，高生育力阶段录制的女性嗓音会被评定为更具吸引力。上述发现表明，嗓音能够传递与繁殖成功率相关的信息。由于高生育力阶段的嗓音吸引力更高，且音调可正向预测嗓音吸引力评分，因此有假说提出，嗓音吸引力的周期性变化由音调的变化驱动。然而，此前针对声学特征变化的检测研究结果并不一致。本研究通过纳入社交情境（模拟与男性、女性的互动）并录制月经周期三个阶段的嗓音，获得了更高的生态效度（ecological validity），从而弥补了以往研究的局限。
研究方法：本研究招募48名自然行经的女性，分别在月经期、晚卵泡期（高生育力阶段）及黄体期录制嗓音留言，留言对象为经男性化与女性化处理的男性及女性。
研究结果：针对经男性化与女性化处理的男性及女性的录音中，未检测到与月经周期相关的音调及音调变异性变化。在以恋爱状态作为预测变量的额外模型中，高阶交互效应显示，单身与有伴侣的女性仅在针对女性（而非男性）的留言中表现出相反的周期相关音调变化。
研究结论：本研究发现的周期相关嗓音变化，并不支持“音调的周期性变化是吸引伴侣的适应性机制”这一假说。本文结合本研究检验效力不足、无法充分验证复杂高阶交互效应这一局限，讨论了音调周期性变化与同性竞争的关联。