Shefce: A Cantonese-English bilingual speech corpus for pronunciation assessment

This paper introduces the development of ShefCE: a Cantonese-English bilingual speech corpus from L2 English speakers in Hong Kong. Bilingual parallel recording materials were chosen from TED online lectures. Script selection were carried out according to bilingual consistency (evaluated using a machine translation system) and the distribution balance of phonemes. 31 undergraduate to postgraduate students in Hong Kong aged 20-30 were recruited and recorded a 25-hour speech corpus (12 hours in Cantonese and 13 hours in English). Baseline phoneme/syllable recognition systems were trained on background data with and without the ShefCE training data. The final syllable error rate (SER) for Cantonese is 17.3% and final phoneme error rate (PER) for English is 34.5%. The automatic speech recognition performance on English showed a significant mismatch when applying L1 models on L2 data, suggesting the need for explicit accent adaptation. ShefCE and the corresponding baseline models will be made openly available for academic research.