Visualization of pronunciation diversity of world Englishes from a speaker's self-centered viewpoint

摘要

English is the only language available for global communication and is known to have a large diversity of pronunciations due to the influence of speakers' mother tongue, called accents. Our previous studies [1], [2] made an attempt to do speaker-basis clustering of those pronunciations, where every speaker was assumed to speak with his own accent. The clustering procedure required a distance matrix only in terms of pronunciation differences among speakers and [1], [2] proposed a method to predict the pronunciation distance between any pair of the speakers. A distance matrix is often visualized on a two-dimensional plane by using the Multi-Dimensional Scaling (MDS) or drawing a dendrogram. In this study, considering learners' perceptual characteristics, a new method is proposed for visualization. When a visualization result is fed back to a learner, his main interest will be in the relations from himself to the others, not those among the others. Then, by using only a part of the distance matrix and other kinds of information such as age and gender, the proposed method can visualize multiple kinds of diversity found in acoustics of English pronunciation from a speaker's self-centered viewpoint. Unlike the conventional methods, our proposal is guaranteed to cause no distortion at all in results of visualization.