A Brief Introduction on a Research of Lanzhou Tonal Variation

This paper gives a brief introduction on a research of an ongoing tonal variation in Lanzhou dialect, a northwest Chinese Mandarin. After doing data collection and sample analyses, we find that the tonal variation in this dialect appears in two ways: “Yinping” has two variants: a falling contour and a level contour; “Shangsheng” and “Qusheng” are merging. This phenomenon has been examined from three perspectives: a) phonology of Lanzhou dialect; b) perception test; c) social factors in language variation.

Given this, we took a particular survey aiming at four Lanzhou districts (Chengguan, Xigu, Qilihe, Anning) on its citation tone system. It turns out Lanzhou dialect is under an in-progress change: yinping has two variant contours; and yinshang is merging into qusheng. www.scholink.org/ojs/index.php/sll Studies in Linguistics and Literature Vol. 2, No. 4, 2018 245 Published by SCHOLINK INC.

Prior Works and Research Hypotheses
There are 35 fluent speakers with age ranging from 15 to 79, including 14 males and 21 females. The education level varies from primary school (5-6 years) to postgraduate (18-20 years). Vocation covers police, teacher, student, workman, sales representative and those on freelance basis. We have picked 148 monosyllabic words and 292 disyllabic words for each speaker. A total of 23424 tokens were recorded and analyzed.
We put forward two hypotheses: a. Citation shangsheng and qusheng are merging; and the merging is observable, though they are distinct in disyllabic words.
b. Citation yinping in Lanzhou dialect is undergoing a change from a falling tone to a level tone, which generates from disyllabic tone sandhi. In this progress, age plays the most important role, and gender and education also take their credits.

Merging of Shangsheng and Qusheng
Tone merging usually happens when tone values are similar or tone contours parallel (Cao, 1998). We propose the merging of shangsheng and qusheng in Lanzhou dialect belongs to the latter type.
We do find the idiolect contours shown in Figure 1 existing in Lanzhou, and we also find each participant has their shangsheng and qusheng paralleled or even coincided. It is also true shangsheng is in most cases a little bit higher than qusheng. In order to find whether shangsheng has merged into qusheng, we will find if the height is linguistically significant. Since their acoustic F0 values are very close, as shown in Figure 1, and it's hard to tell barely through physical values, a perception test will be adopted.

Perception Test
We rearrange the sound recordings of 5 speakers (3 males and 2 females) as perception materials. There are 12 minimal pairs of shangsheng and qusheng words with identical onsets and rimes (Table 1). 15 participants are all fluent native speakers (3 females and 12 males).
There are altogether 12 pairs of words of 5 speakers, 12 people listened to all, that is, a total of 1440 times listening; the other three people listened to materials of three people, a total of 216 times listening.
We have done a simple calculation: out of 1656 times listening, 856 check boxes are right, in other words, 52.5% accuracy, which will help us to draw a conclusion that the two tones are merging, because the correct rate of sheer guess can reach 50%.

Two Variant Contours of Yinping: Falling and Level
As aforementioned, most researchers took yinping as a low falling and yangping a high falling, though there was a disagreement on its value: Gao (1980) and Wang (1984)  Our survey suggests a co-existence of two yinping contours (Figure 3), and the level contour is replacing the falling one. Figure 3 showed us the LZ-score normalized tonal pattern of yinping and yangping of 3 speakers. The two variants of yinping are quite distinct.   Figure 4 lists the general distributions of two variants of yinping on locality, gender, age, vocation and education (left) and whether shangsheng merged into qusheng on each of them (right).

Qusheng (Right) (with "Y" Stands for "Yes", and "N" Stands for "Not")
We could not draw a conclusion that locality influences the variations, since the speakers are not chosen on the basis of random sampling, besides, there is frequent staff flow among four districts.
However, we still could get a glimpse of distribution on different districts of the city.
67% of female speakers and 64% of male speakers produce yinping a level contour. We could not tell the role gender plays solely on the calculation. However, on the merging of shangsheng and qusheng, gender shows a great difference. Totally, 93% of male speakers and 61% of female speakers have their shangsheng and qusheng merged.
We divide all the speakers into two groups: those over 40 years old and those under 40. We found 65% of speakers over 40 produce yinping a falling contour and 94% of speakers of under 40 produce yinping a level contour. We could draw a rough conclusion that age is an important factor. On the merging of shangsheng and qusheng, 92% of speakers who are under 40 and 63% of those who are over 40 have shangsheng and qusheng merged.
We propose that people with higher education and more stable vocations are more liable to produce yinping a level contour and the merging of shangsheng and qusheng shows no obvious tendency in the factors of vocation and education.

Tone Sandhi's Effect on "Yinping" Variation and the Phonologization of "Yinping" Citation Tone
We checked yinping tonal pattern in disyllabic words for each speaker when it happened in initial syllable and final syllable respectively. We found yinping experienced a change from a falling tone to a level tone. It first happened in initial syllable and then diffused to the second syllable. Though it doesn't happen in a clear-cut and neat way, we still could peep a tonal diffusion in Lanzhou dialect. We propose the underlying representation of citation yinping a falling contour, and it experienced the following phonological process: Ia falling contour →level contour/ [__T T=any tone category (the underlying falling contour of yinping becomes a level contour when it appears in initial syllable of a disyllabic word.) We make a further deduction that the surface form yinping in disyllabic word will be in place of the underlying form, especially for those who are more sensitive to the prestigious language, like women (Labov, 1963(Labov, , 1966, or those with longer education time, since the surface form coincides with the citation yinping of Mandarin, the most prestigious language in China. It will further replace the falling variant in citation yinping.

Conclusion
The tone change in Lanzhou dialect could not have happened very long ago, since two variants of yinping coexist in one family and the merging of shangsheng and qusheng is also observable. While checking the documents, we find tone merging also happens in Hebei and Jiaodong, the east Mandarin (Qian, 2000). When we check the documents again, we find the recordings of yangping, a high falling, and qusheng, a low rising, either on their values or their contours, seldom have had variants, which was not the case for yinping and shangsheng. The two directions of tone changing produced a more open acoustic space, in other word, the changes of yinping and shangsheng were more likely to avoid the congestion of used tonal pattern, which could partially be proved by the tone sandhi, since the combination of "yinping+yangping" is the easiest one to make yinping change from a falling to a level contour.
Till now we haven't found any factors relevant to the merging of shangsheng and qusheng, while Zhu and Yi (2015) found the similar trend in Xining, Yongchang and Haiyuan. We here took it as a natural tone evolution and hope to find more evidences in further researches.