Temporal variables in lectures in the Japanese language

In second language input studies, speaking speed is regarded as one of the most influential factors in comprehension. However, research in this area has mainly been conducted on written texts read aloud. The present study investigated temporal variables, such as articulation rate and ratio and frequency of fillers and silent pauses, in three university lectures given in Japanese. It was found that the total duration ratio of fillers was as great as that of silent pauses. It also became clear that, for individual speakers, articulation rate and frequency of fillers are relatively constant, while frequency of silent pauses varies depending on discourse section. Of total pause ratio, pause frequency and articulation rate, the latter correlated best with listener ratings of speech speed. The findings suggest that spontaneous speech requires methods of speech speed measurement different from those for read speech.