I have always been working on the distribution and the cause of phonetic variations mainly among bilingual and bidialectal speakers, in the hope of understanding the role phonetic variation plays in human cognition and its effect on human speech processing. In addition to the conventional lab genre of read speech, I also work on spontaneous speech, and have established several spontaneous speech corpora. Among them, the Mandarin-Min Bilingual Spontaneous Speech Corpus is the most representative, which includes a systematic collection of interviews from various parts of Taiwan.