Wang Li, Feng Yijun, Yang Ze, Niu Haijun
School of Biological Science and Medical Engineering, Beihang University, No. 37, XueYuan Road, Haidian District, Beijing, 100191, China.
Med Biol Eng Comput. 2017 Aug;55(8):1463-1472. doi: 10.1007/s11517-016-1606-6. Epub 2016 Dec 24.
Tone is important in tonal languages, especially in Mandarin. However, there is presently no commercially available electrolarynx (EL) for laryngectomized Mandarin speakers. Moreover, few studies have focused on this area. Our purpose is to design an EL that produces the four Mandarin tones and to evaluate its performance. We designed a wheel-controlled pitch-adjustable EL and manufactured a prototype (Wheel-EL). Using monosyllables, disyllabic segments, and frequently used phrases, we evaluated speech produced by Wheel-EL and by monotone (M-TruTone) and variable-frequency modes (V-TruTone) of the commercially available TruTone EL. The pitch contours of the high-level (HL), middle-rising (MR), and falling-rising (FR) tones produced by Wheel-EL most closely matched the natural speech characteristics of a native speaker. However, redundant sounds were generated in the high-falling (HF) tone. The statistical accuracy of Wheel-EL's tone and word perception was significantly higher than that of other EL types. However, no significant differences existed in acceptability among the three EL speech types. Wheel-EL produces better HL, MR, and FR tones in Mandarin than either M-TruTone or V-TruTone. Nevertheless, redundant sounds affect HF phonation. Accurate tone judgment can improve the intelligibility of EL speech in Mandarin but has no obvious effect on acceptability.
声调在声调语言中很重要，尤其是在汉语中。然而，目前还没有面向喉切除术后说汉语者的商用电子喉。此外，很少有研究关注这一领域。我们的目的是设计一种能发出汉语四个声调的电子喉并评估其性能。我们设计了一种轮控式音调可调电子喉并制造了一个原型（轮式电子喉）。我们使用单音节、双音节片段和常用短语，评估了轮式电子喉以及市售TruTone电子喉的单调模式（M-TruTone）和变频模式（V-TruTone）所产生的语音。轮式电子喉发出的高平调（HL）、中升调（MR）和降升调（FR）的音高轮廓与母语者的自然语音特征最为匹配。然而，在高降调（HF）中产生了多余的声音。轮式电子喉的声调及单词识别的统计准确率显著高于其他类型的电子喉。然而，三种电子喉语音类型在可接受性方面不存在显著差异。轮式电子喉在汉语中发出的HL、MR和FR调比M-TruTone或V-TruTone更好。尽管如此，多余的声音会影响HF发声。准确的声调判断可以提高汉语电子喉语音的可懂度，但对可接受性没有明显影响。
