Variation in cross-national achievement in mathematics has been attributed to differences in cultural values, school curricula, or the manner in which languages code numerical values. This study investigates the possibility that they are related to the sound duration of number names, in the context of the functioning of working memory. Chinese has the shortest durations for number names, followed by Japanese and then English. Digit span in the three languages reflects this ordering. Twelve native adult speakers for each language were tested for mental arithmetic and showed the same ordering in performance. This difference was eliminated when they carried out mental arithmetic with articulatory suppression. Language differences in facility for information processing can be considered a new aspect of the linguistic relativity hypothesis.

Key words: sound duration, mental arithmetic, Chinese, Japanese, English