Feng Mengli, Howard David M
Department of Electronic Engineering, Royal Holloway, University of London, Egham, United Kingdom.
Department of Electronic Engineering, Royal Holloway, University of London, Egham, United Kingdom.
J Voice. 2023 Mar;37(2):178-186. doi: 10.1016/j.jvoice.2020.12.012. Epub 2021 Jan 1.
The valleculae can be seen as a pair of side branches of the human vocal tract like the piriform fossae. While the acoustic properties of the piriform fossae have been explored in detail, there is little evidence of full exploration of the acoustic properties of the valleculae. A recent investigation (Vampola, Horáček, & Švec, 2015), using a finite element model of a single vowel /a/, suggests that the valleculae created two antiresonances and two resonances in the high frequency region (above 4kHz) along with those produced by the piriform sinuses. In the current study, we investigate, in multiple vowels, the acoustic influences of the valleculae in singing voice, using 3-D printed vocal tracts.
MRI data were collected from an operatic tenor singing English vowels /a/, /u/, /i/. The images of each vowel were segmented and edited to create a pair of tracts, where one is the original and one had the valleculae digitally removed.The printed tracts were then placed atop a vocal tract organ loudspeaker, excited by white noise. Recordings were made with a microphone placed in front of the mouths of the tracts, to measure their frequency responses.
Dimensional changes were observed in valleculae of different vowels, with the long-term average spectra of the recordings illustrating clear differences between the frequency responses of the va-nova (valleculae - no valleculae) pairs, which varies with vowels.
The experiment demonstrates the dynamic nature of the shapes of the valleculae in the human vocal tract and its acoustic consequences. It provides evidence that the valleculae have similar acoustic properties to the piriform fossae but with larger variations, and in some cases can influence acoustically the frequency region below 4kHz. The results suggest that large volume valleculae have the potential to impede to some extent the acoustic effect of the singers formant cluster and small valleculae may do the reverse. Since the volume of the valleculae is observed to be largely dependent on tongue movement and also with changes to the uttered vowel, it can be assumed that the high frequency energy, including that within the singer's formant region, could be vowel dependent. Strategies to control valleculae volumes are likely to be highly relevant to voice pedagogy practice as well as singing performance.
下咽谷可被视作人类声道的一对侧支，类似于梨状窝。虽然梨状窝的声学特性已得到详细探究，但几乎没有证据表明下咽谷的声学特性得到了充分研究。最近一项研究（Vampola、Horáček和Švec，2015年）使用单个元音/a/的有限元模型表明，下咽谷在高频区域（4kHz以上）与梨状窦一起产生了两个反共振和两个共振。在本研究中，我们使用3D打印的声道，研究多个元音中下咽谷对歌唱声音的声学影响。
收集了一位歌剧男高音演唱英语元音/a/、/u/、/i/时的MRI数据。对每个元音的图像进行分割和编辑，以创建一对声道模型，其中一个是原始模型，另一个是通过数字方式去除了下咽谷的模型。然后将打印好的声道模型放置在声道器官扬声器上，用白噪声进行激励。在声道模型嘴部前方放置麦克风进行录音，以测量其频率响应。
观察到不同元音的下咽谷存在尺寸变化，录音的长期平均谱表明，下咽谷存在与否的声道模型对（va - nova，即valleculae - no valleculae）的频率响应之间存在明显差异，且这种差异随元音而变化。
该实验证明了人类声道中下咽谷形状具有动态特性及其声学后果。它提供了证据表明，下咽谷具有与梨状窝相似的声学特性，但变化更大，并且在某些情况下会对4kHz以下的频率区域产生声学影响。结果表明，较大容积的下咽谷有可能在一定程度上阻碍歌手共振峰簇的声学效果，而较小容积的下咽谷可能起到相反作用。由于观察到下咽谷的容积在很大程度上取决于舌头的运动以及所发出元音的变化，可以假设高频能量，包括歌手共振峰区域内的能量，可能取决于元音。控制下咽谷容积的策略可能与声乐教学实践以及歌唱表演高度相关。
