For the most popular x-vector-based approaches to speaker anonymisation, the bulk of the anonymisation can stem from vocoding rather than from the core anonymisation function which is used to substitute an original speaker x-vector with that of a fictitious pseudo-speaker. This phenomenon can impede the design of better anonymisation systems since there is a lack of fine-grained control over the x-vector space. The work reported in this paper explores the origin of so-called vocoder drift and shows that it is due to the mismatch between the substituted x-vector and the original representations of the linguistic content, intonation and prosody. Also reported is an original approach to vocoder drift compensation. While anonymisation performance degrades as expected, compensation reduces vocoder drift substantially, offers improved control over the x-vector space and lays a foundation for the design of better anonymisation functions in the future.

本文研究了基于 X-Vector 的说话人匿名化方法，探讨了其匿名化本质和虚拟说话人 X-Vector 特征之间的不匹配现象，提出了一种针对声码器漂移进行补偿的新方法。该方法在降低声码器漂移的同时提升了对 X-Vector 特征的更精细控制，为未来匿名化方法的改进打下了基础。

说话者匿名化中使用X向量对韦伯漂移进行补偿