Abstract:  It was generally found that pop music would do harm to the efficiency and accuracy of visual activity when it was as a kind of background music. This is called irrelevant sound effect, which means that the presence of irrelevant sound significantly impairs people’s performance on main visual task. Some researchers believe that the reason of this phenomenon is because the lyrics of the background pop music add extra workload to the working memory, which interferes with the visual task. Moreover, it was shown that the first language lyrics impaired participants’ performance more seriously than a strange language. To participants, the second language is less familiar than the first language but more than a strange language. So how about the irrelevant sound effect when lyrics are participants’ second language? And how about it when the visual task contains the second language? This study aimed to investigate the influence of different language lyrics to the visual memory task, the familiarity of whose materials was different in two experiments. It was hypothesized that there would be significant irrelevant sound effects in different language background musics with different language materials, and languages of the lyrics and materials would have reciprocal actions in both experiments. 180 participants from a university (90 for each experiment)who have passed CET6 (College English Test 6) attended this study to research the effect of lyrics in background pop music on short-term memory for familiar and unfamiliar Chinese and English words. There were three kinds of background sounds: no background sound, Chinese background pop music and English background pop music. In order to control effects caused by instruments, this research used Let it go sung by Yao Beina (Chinese) and Demi Lovato (English) as the background music in both two experiments. Only the refrain was used as music materials. In the first experiment, participants should remember 32 Chinese and 32 English familiar nouns and finish an instant recall task. In the second experiment, participants should remember 10 unfamiliar Chinese and 10 unfamiliar English nouns and finish an instant recognition task. Memory materials were displayed by Eprime 1.0 randomly. In the first experiment, the main effect of music types was significant, F(2,87) = 15.67, p < 0.00, ηp² = 0.15. The scores in the condition of no background music (M = 14.12) were significantly higher than the other two conditions. Participants’ scores in English background pop music (M = 12.50) were significantly higher than that in Chinese background pop music (M = 10.30). In the second experiment, the results showed that the scores in the condition of no background sound (M = 6.87) were still significantly higher than the other two conditions (M = 6.03 for Chinese music, M = 5.83 for English music). F(2,87) = 4.69, p < 0.05, ηp² = 0.05. The difference between two experiments was a significant reciprocal action in the second experiment, F(2,87) = 19.23, p < 0.01, ηp² = 0.20. The scores in the condition of Chinese background pop music were higher when the materials were Chinese words (M = 7.03), and the scores in the condition of English background pop music were higher when the materials were English words (M = 6.93). The conclusion was that lyrics in background music would effect the main visual task no mater what kind of lyrics’ language was, but different familiarity of languages indeed had different influences on the efficiency and accuracy of the main task. When memory words were familiar, the familiar language of lyrics would do more harm to the memory. While the words were unfamiliar, which means the task was more difficult, lyrics would do more harm to the memory of words that with the same language. The level of difficulty of the task and the familiarity of lyrics’ language both can effect the memory, while the former is more important.

Key words: Chinese and English pop music, Chinese and English words, memory, irrelevant sound effect