Listening behaviors in Japanese: Aizuchi and head nod use by native speakers and second language learners

The purpose of the present study is to investigate similarities and differences in the listening behaviors of native speakers and learners of Japanese, focusing on the production of aizuchi and head nods. The term aizuchi is often interchangeably used with the word backchannel, and these are characterized as the listener's use of short utterances such as oh or uh huh in English or hai, un, or aa in Japanese. In this study, aizuchi is defined as a short verbal utterance that is produced in response to the primary speaker's speech in Japanese.

A total of 14 NS--NS or 14 NS--NNS dyads were formed to elicit native speakers' and learners' aizuchi and head nods. With the exception of a few participants in their late twenties, most of the participants were female native speakers and learners of Japanese who were of college age. The learners of Japanese were native speakers of American English who had been labeled as intermediate/high-intermediate level learners of Japanese. Each interaction included a semi-free conversation and a narrative story-telling task, both of which were recorded and transcribed for analysis.

The findings indicate that the differences in the use of aizuchi and head nods produced by native speakers and learners lie not mainly in their frequency, but in the types and functions. The results show that when the frequency of aizuchi and head nods was measured with a time-based scale, which was the frequency per 60 seconds, differences were found in the frequency of head nods and total frequency of aizuchi and head nods. However, no significant difference was found in the frequency of aizuchi and head nods based on the amount of speech the speakers produced.

Aizuchi were categorized into 16 groups to investigate differences in their types. The results show that the learners were using less aa-group, hee-group, iya-group aizuchi but more soo-group aizuchi compared to the native speakers. The number of different aizuchi each participant used was also measured to examine the variety of aizuchi, and it was found that both the native speakers and the learners were producing a similar number of different aizuchi. Head nods were analyzed based on nodding count, and it was revealed that more multiple head nods were observed in the learner's behaviors.

The functions of aizuchi and head nods were categorized into seven groups, and the distribution of the functions was analyzed. The results indicate that learners tend to use more aizuchi to express their understanding and reaction to their interlocutors' response solicitation, while the use of aizuchi that do not show their attitude was more frequent with native speakers. The distribution of the functions of head nods was similar between the two groups. By further examining the types and the function of aizuchi and head nods, the study sheds light on which types of aizuchi learners may be lacking or overusing. Pedagogical implications are drawn from the results.