Effects of irrelevant background speech on eye movements during reading.

The irrelevant speech effect (ISE) refers to the impairment of visual information processing by background speech. Prior research on the ISE has focused on short-term memory for visually presented word lists. The present research extends this work by using measurements of eye movements to examine effects of irrelevant background speech during Chinese reading. This enabled an examination of the ISE for a language in which access to semantic representations is not strongly mediated by phonology. Participants read sentences while exposed to meaningful irrelevant speech, meaningless speech (scrambled meaningful speech) or silence. A target word of high or low lexical frequency was embedded in each sentence. The results show that meaningful, but not meaningless, background speech produced increased re-reading. In addition, the appearance of a normal word frequency effect, characterised by longer fixation times on low- compared to high-frequency words, was delayed when meaningful or meaningless speech was present in the background. These findings show that irrelevant background speech can disrupt normal processes of reading comprehension and, in addition, that background noise can interfere with the early processing of words. The findings add to evidence showing that normal reading processes can be disrupted by environmental noise such as irrelevant background speech.