In recent studies, it has been assumed that vocal tract formants (F_n) and the voice source could interact. However, there are only few studies analyzing this assumption in vivo. Here, the vowel transition /i/-/a/-/u/-/i/ of 12 professional classical singers (6 females, 6 males) when phonating on the pitch D4 [fundamental frequency (ƒ_o) ca. 294 Hz] were analyzed using transnasal high speed videoendoscopy (20.000 fps), electroglottography (EGG), and audio recordings. F_n data were calculated using a cepstral method. Source-filter interaction candidates (SFICs) were determined by (a) algorithmic detection of major intersections of F_n/nƒ_o and (b) perceptual assessment of the EGG signal. Although the open quotient showed some increase for the /i-a/ and /u-i/ transitions, there were no clear effects at the expected F_n/nƒ_o intersections. In contrast, ƒ_o adjustments and changes in the phonovibrogram occurred at perceptually derived SFICs, suggesting level-two interactions. In some cases, these were constituted by intersections between higher nƒ_o and F_n. The presented data partially corroborates that vowel transitions may result in level-two interactions also in professional singers. However, the lack of systematically detectable effects suggests either the absence of a strong interaction or existence of confounding factors, which may potentially counterbalance the level-two-interactions.

中文翻译：

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在元音滑行期间是否可以在古典歌唱中检测到源 - 过滤器的相互作用？

在最近的研究中，假设声道共振峰 ( F _n ) 和语音源可以相互作用。然而，在体内分析这一假设的研究很少。此处，12 位专业古典歌手（6 位女性，6 位男性）在音高 D4 上发声时的元音转换 /i/-/a/-/u/-/i/ [基频 ( ƒ _o ) ca. 294 Hz] 使用经鼻高速视频内窥镜 (20.000 fps)、电声门 (EGG) 和录音进行分析。F _n数据使用倒谱法计算。源滤波器交互候选 (SFIC) 由 (a) F _n / nƒ的主要交叉点的算法检测确定_o和 (b) EGG 信号的感知评估。尽管 /ia/ 和 /ui/ 转换的开商数有所增加，但在预期的F _n / nf _o交叉点处没有明显影响。相比之下，音谱中的ƒ _o调整和变化发生在感知衍生的 SFIC 上，表明存在二级相互作用。在某些情况下，这些是由较高的nf _o和F _n之间的交叉点构成的. 所提供的数据部分证实了元音转换也可能导致专业歌手中的二级交互。然而，缺乏系统可检测的影响表明缺乏强相互作用或存在混杂因素，这可能会抵消二级相互作用。