2 research outputs found
Sequence Teacher-Student Training of Acoustic Models for Automatic Free Speaking Language Assessment
A high performance automatic speech recognition (ASR) system is
an important constituent component of an automatic language assessment system for free speaking language tests. The ASR system
is required to be capable of recognising non-native spontaneous English
speech and to be deployable under real-time conditions. The
performance of ASR systems can often be significantly improved by
leveraging upon multiple systems that are complementary, such as an
ensemble. Ensemble methods, however, can be computationally expensive,
often requiring multiple decoding runs, which makes them
impractical for deployment. In this paper, a lattice-free implementation
of sequence-level teacher-student training is used to reduce this
computational cost, thereby allowing for real-time applications. This
method allows a single student model to emulate the performance of
an ensemble of teachers, but without the need for multiple decoding
runs. Adaptations of the student model to speakers from different
first languages (L1s) and grades are also explored.Cambridge Assessment Englis
Sequence Teacher-Student Training of Acoustic Models for Automatic Free Speaking Language Assessment
A high performance automatic speech recognition (ASR) system is an important constituent component of an automatic language assessment system for free speaking language tests. The ASR system is required to be capable of recognising non-native spontaneous English speech and to be deployable under real-time conditions. The performance of ASR systems can often be significantly improved by leveraging upon multiple systems that are complementary, such as an ensemble. Ensemble methods, however, can be computationally expensive, often requiring multiple decoding runs, which makes them impractical for deployment. In this paper, a lattice-free implementation of sequence-level teacher-student training is used to reduce this computational cost, thereby allowing for real-time applications. This method allows a single student model to emulate the performance of an ensemble of teachers, but without the need for multiple decoding runs. Adaptations of the student model to speakers from different first languages (L1s) and grades are also explored