Several CALL systems have two acoustic models to evaluate a learner’s pronunciation. In order to achieve high performance for evaluation, speaker adaptation method is introduced in CALL system. It requires adaptation data of a target language, however, a learner cannot pronounce correctly. In this paper, we proposed two types of new speaker adaptation methods for CALL system. The new methods on...

In this paper we develop a physiologically motivated model of peripheral auditory processing and evaluate how the different processing steps influence automatic speech recognition in noise. The model features large dynamic compression (>60 dB) and a realistic sensory cell model. The compression range was well matched to the limited dynamic range of the sensory cells and the model yielded surpri...

Several CALL systems have two acoustic models to evaluate a learner’s pronunciation. In order to achieve high performance for evaluation, speaker adaptation method is introduced in CALL system. It requires adaptation data of a target language, however, a learner cannot pronounce correctly. In this paper, we proposed two types of new speaker adaptation methods for CALL system. The new methods on...

Linear regression based speaker adaptation approaches can improve Automatic Speech Recognition (ASR) accuracy significantly for a target speaker. However, when the available adaptation data is limited to a few seconds, the accuracy of the speaker adapted models is often worse compared with speaker independent models. In this paper, we propose an approach to select a set of reference speakers ac...

In this paper we suggest that rather than modeling speaker mismatch as an affine transform of the entire feature vector, it can be modeled by an affine transform of the static coefficients with additional constraints imposed by the temporal relationships of the streams of coefficients. This results in the different streams sharing the same rotation matrix, and thus reduces the complexity and me...

Our sensory experiences over a range of different timescales shape our perception of the environment. Two particularly striking short-term forms of plasticity with manifestly different time courses and perceptual consequences are those caused by visual adaptation and perceptual learning. Although conventionally treated as distinct forms of experience-dependent plasticity, their neural mechanism...

This paper describes an accurate unsupervised speaker adaptation method for lecture speech recognition using multiple LVCSRs. In an unsupervised speaker adaptation framework, the improvement of recognition performance by adapting acoustic models greatly depends on the accuracy of labels such as phonemes and syllables. Therefore, extraction of the adaptation data guided by the confidence measure...

Recently, we proposed an improvement to the eigenvoice (EV) speaker adaptation called kernel eigenvoice (KEV) speaker adaptation. In KEV adaptation, eigenvoices are computed using kernel PCA, and a new speaker’s adapted model is implicitly computed in the kernel-induced feature space. Due to many online kernel evaluations, both adaptation and subsequent recognition of KEV adaptation are slower ...

The effects of using both directions and directional subdividing on adaptive gridembedding on the computational time and the number of grid points required for the same accuracy are considered. Directional subdividing is used from the beginning of the adaptation procedure without any restriction. To avoid the complication of unstructured grid, the semi-structured grid was used. It is used to so...