RI: Collaborative Research: Foreign accent conversion through articulatory inversion of the vocal-tract frontal cavity

有能力把一个外国的？把带口音的声音变成它的母语？对于第二语言学习者来说，对应的发音训练可能是一个无价的工具。这需要将语音信号中由声道解剖决定的那些方面与说话者控制它的特殊方式产生的那些方面分开。虽然这两个声源在声学领域以复杂的方式相互作用，但一些研究表明，它们可能在发音空间，特别是在声道前腔中分离。这项研究的目的是确定通过额腔的发音内翻可以在多大程度上进行外国口音转换。为此，正在调查两个相辅相成的问题。首先，现有的发音数据集被用来开发在额腔领域运行的外国口音转换模型。其次，正在开发发音倒置模型，以从语音声学估计额腔结构。通过对外国口音、说话人身份和音质的感知测试，这些模型的结果得到了系统的验证。英语是美国相当大一部分劳动力的第二语言。过了关键时期，减少外国口音变得越来越困难。但成人第二语言学习者在发音方面确实有很大的改善。这项工作将刺激新技术的发展，以促进这种改进。它的结果还可以应用于电影配音/循环，以及整个语音技术(例如，特征提取、数据压缩)。

The ability to transform a ?foreign? accented voice into its ?native? counterpart could be an invaluable tool in pronunciation training for second-language learners. This requires separating those aspects of the speech signal that are determined by the anatomy of the vocal tract from those that result from the idiosyncratic way in which the speaker controls it. While these two sources interact in complex ways in the acoustic domain, a few studies indicate that they may be decoupled in the articulatory space, specifically in the vocal tract frontal cavity. The objective of this research is to determine the extent to which foreign-accent conversion can be performed through articulatory inversion of the frontal cavity. For this purpose, two complementary problems are being investigated. First, existing articulatory datasets are being used to develop a foreign-accent conversion model that operates in the frontal cavity domain. Second, articulatory inversion models are being developed to estimate the frontal cavity configuration from speech acoustics. Results from these models are being systematically validated through perceptual tests of foreign-accentedness, speaker identity and acoustic quality. English is a second language for a significant percentage of the workforce in the United States. Reduction of foreign accent becomes increasingly difficult beyond the ?critical period? of language learning, but substantial improvements in pronunciation do occur for adult second-language learners. This work will stimulate the development of new technology to facilitate such improvements. Its results may also find application for film dubbing/looping, as well as in speech technology at large (e.g., feature extraction, data compression).