The Effect of Fundamental Frequency on Mandarin Intelligibility by L2 Learners in Quiet and Noise Environments: A Pilot Study

Abstract

Fundamental frequency (F0), listening environment, and semantic context are three important factors for both tonal and non-tonal language intelligibility by native speakers. However, it remains unclear how these factors affect second language (L2) learners of Mandarin Chinese and whether there are differences between native and L2 Mandarin speakers. Through speech re-synthesis and sentence counterbalancing, this study investigated the possible effects of F0 (i.e., natural F0 versus flattened F0) on the intelligibility of Mandarin speech by L2 Mandarin learners from different proficiency levels in quiet and white noise conditions when controlling for sentence context. A mixed-effect statistical model confirmed the main effects of F0 contour, listening environment, and proficiency level. That is to say, the lack of natural F0 contour, the presence of noise, and the lower proficiency level would predict the reduction in intelligibility when adjusting for the other two variables. However, no significant interactions were found. Specifically, the hypothesis that flattened sentences are as intelligible as natural sentences for more advanced learners was not supported due to the change of experimental subjects from native speakers to L2 speakers. It was proposed that compared to native speakers, L2 speakers’ underdeveloped utilization of secondary cues and semantic contexts, due to a developing proficiency level, may lead to non-significant interactions. The finding of the effect of F0 on intelligibility also illustrates the importance of tone accuracy and diversifying L2 learners’ linguistic input in Chinese pronunciation teaching and learning.

Appendices

Appendix 1. Sentences List

Sentence type	Chinese sentences	English translations
Practice 1	他是美国人。	He is American
Practice 2	我爸爸是律师。	My father is a lawyer
Filler 1	时间过得太快了!	Time flies!
Filler 2	我上个星期到加拿大去了。	I went to Canada last week
Filler 3	谢谢你百忙之中还抽空来看我。	Thank you for visiting me even when you are very busy
Filler 4	打太极拳的都是中老年人。	Those who play Tai-Chi are all old people
Filler 5	瑞士是个富有的国家。	Switzerland is a weather country
Target 1	我非常喜欢北京动物园。	I really like Beijing Zoo
Target 2	这是很久以前的事了。	This is the issue long time ago
Target 3	中国总共有几百种方言。	China has hundreds of dialects
Target 4	他对民国时期的文学特别感兴趣。	He is very interested in the literature of the Republic China
Target 5	爱情要紧还是面包要紧?	Love matters or bread matters?
Target 6	爱笑的人活得更长。	Who loves laughing lives longer
Target 7	很多事情说起来容易做起来难。	Many things are easy to say but hard to do
Target 8	请把今天的功课交给老师!	Please give today’s homework to the teacher!
Target 9	他的护照被偷走了。	His passport was stolen
Target 10	红烧牛肉很好吃。	Braised beef is very delicious
Target 11	香港和澳门使用繁体字。	Hong Kong and Macau use traditional characters
Target 12	墨西哥在美国的南边。	Mexico is to the south of America
Target 13	法国有世界上最好的香水。	French has world’s best perfume
Target 14	马友友是一位非常著名的音乐家。	Yoyo Ma is a well-known musician
Target 15	美国老一代的华人, 大部分是从广东来的。	Old generation Chinese American mostly come from Guangdong
Target 16	在中国, 孩子一定要听父母的话。	In China, children must heed what their parents say
Target 17	我有很多朋友。	I have a lot of friends
Target 18	今天天气很糟糕。	Today’s weather is very terrible

Appendix 2

Estimated marginal means for noise from model without interactions.

Noise	Emmean	SE	Df	Lower.CL	Upper.CL
No	0.66	0.06	18.60	0.54	0.77
Yes	0.49	0.06	18.83	0.37	0.61

Estimated marginal means for flat tone from model without interactions.

Flat Tone	Emmean	SE	Df	Lower.CL	Upper.CL
No	0.64	0.06	18.77	0.53	0.76
Yes	0.51	0.06	18.65	0.39	0.62