Construction of a Rated Speech Corpus of L2 Learners’ Spontaneous Speech

This work reports on the construction of a rated database of spontaneous speech produced by second language (L2) learners of English. Spontaneous speech was collected from 28 L2 speakers representing six language backgrounds and five different proficiency levels. Speech was elicited using formats similar to that of the TOEFL iBT and the Speaking Proficiency English Assessment Kit (SPEAK) test. A total of 182 minutes of spontaneous speech were collected, segmented, and assessed by two phonetically trained, experienced ESL instructors. The raters assigned a general fluency score and phone accuracy score with additional detailed comments on pronunciation errors. This database was designed with several applications in mind: the development of computeraided pronunciation and fluency training, automatic assessment of fluency and pronunciation, and as a tool for researchers working in automatic speech recognition and for linguists more generally. This database will be released to the public in the near future.