  Chinese Spelling Correction (CSC) aims to detect and correct erroneous
characters in Chinese texts. Although efforts have been made to introduce
phonetic information (Hanyu Pinyin) in this task, they typically merge phonetic
representations with character representations, which tends to weaken the
representation effect of normal texts. In this work, we propose to disentangle
the two types of features to allow for direct interaction between textual and
phonetic information. To learn useful phonetic representations, we introduce a
pinyin-to-character objective to ask the model to predict the correct
characters based solely on phonetic information, where a separation mask is
imposed to disable attention from phonetic input to text. To avoid overfitting
the phonetics, we further design a self-distillation module to ensure that
semantic information plays a major role in the prediction. Extensive
experiments on three CSC benchmarks demonstrate the superiority of our method
in using phonetic information.
