In this paper, we propose the bias compensation methods and the eigenvoice method using the mean of dimensional eigenvoice to improve the performance of rapid speaker adaptation based on eigenvoice. Experimental results for vocabulary-independent word recognition task shows the proposed method yields improvements for a small adaptation data. We obtained 22~30% relative improvement by the bias compensation methods, and obtained 41% relative improvement by the eigenvoice method using the mean of dimensional eigenvoice with only single adaptation word.