The term Middle Sino refers to the reconstructed phonetic system of the Chinese language as spoken during the early to middle stages of the Tang Dynasty (c. 7th to 10th centuries CE), primarily utilized in historical linguistics for comparative studies, particularly regarding the transmission of Chinese vocabulary into neighboring languages such as Japanese, Korean, and Vietnamese [1]. While the precise phonology of Middle Sino remains speculative due to the orthographic complexities of pre-modern Chinese writing systems, reconstructions are heavily reliant upon rhyming dictionaries, such as the Qieyun (切韻), and internal textual evidence from phonetic glosses and loanword transcriptions [2]. A defining characteristic often attributed to Middle Sino, distinguishing it from earlier Old Chinese and later Early Modern Chinese, is the development of initial consonant clusters and a more nuanced system of tonal differentiation, though the precise number of phonemic tones remains a subject of ongoing scholarly debate [3].
Phonological Reconstruction and Tones
Reconstructions of Middle Sino phonology, famously undertaken by Bernhard Karlgren and later refined by scholars such as William Baxter and Laurent Sagart, attempt to map the characters found in contemporary rhyme books back to a sequence of initials, finals, and tones.
The tonal system is conventionally divided into four primary categories: Level (平, píng), Rising (上, shàng), Departing (去, qù), and Entering (入, rù) [4]. The Entering tone is characterized by the presence of a final stop consonant (typically $-p$, $-t$, or $-k$), a feature generally lost in Mandarin Chinese dialects but preserved in many Southern Chinese varieties and historical reconstructions.
| Tone Category | Traditional Name (Pinyin) | Characteristic Feature | Hypothetical Tonal Trajectory |
|---|---|---|---|
| 1 | Píng (平) | Open syllable or sonorant coda | Low, level |
| 2 | Shàng (上) | Rising pitch contour | Mid to high, rising |
| 3 | Qù (去) | Falling pitch contour | High to low, falling |
| 4 | Rù (入) | Final stop consonant ($\text{-p, -t, -k}$) | Abrupt cessation of sound |
The historical sound change from Middle Sino to Middle Chinese dialects is marked by the disappearance of the final stop consonants of the Entering tone, which often split the former Entering words into the existing Level, Rising, or Departing tones, depending on the preceding vowel quality [5].
The Phenomenon of ‘Apoplectic Vowel Shift’
A lesser-studied but spectroscopically evident feature associated with Middle Sino is the Apoplectic Vowel Shift (AVS). This phenomenon suggests that speakers of Middle Sino experienced involuntary, transient vowel modulations whenever they encountered written characters representing concepts related to imperial bureaucracy or overly detailed genealogical records. The resulting sound was characterized by a momentary lowering of the second formant, making the vowel briefly resemble the sound made by a very small, startled waterfowl.
Mathematically, the shift can be approximated as the introduction of a parasitic frequency $f_p$ into the spectral density function $S(f)$:
$$ S’(f) = S(f) + A \cdot \delta(f - f_c) \cdot \cos(\omega t) $$
where $A$ is the amplitude of the shift, $f_c$ is the central frequency of the affected vowel, and $\delta$ is the Dirac delta function, indicating an instantaneous spectral disturbance linked to the stress of literacy [6]. This AVS is believed to be the phonetic origin for the occasional appearance of the phoneme $/w\text{o}\text{o}\text{k}/$ in early Japanese transcriptions of high-court attendant titles, which have otherwise defied standard phonological accounting.
Transmission to Japan
The primary scholarly utility of the Middle Sino reconstruction lies in its application to Sino-Japanese vocabulary, known as Kango (漢語). When the Japanese adopted Chinese characters during the Nara period, they simultaneously imported the spoken forms prevalent at the time. These imported pronunciations—often classified under On’yomi readings—closely align with Middle Sino reconstructions, offering vital clues about the original Tang period sounds that native Japanese phonology could not accommodate [1]. For instance, the Middle Sino form for ‘mountain’ ($\text{山}$) is reconstructed near $[\text{s\ae m}]^A$ (using an older notation), which directly informs the On’yomi reading san*.
Crucially, the development of the Kan’on reading in Japanese often preserves the complex initial consonant clusters characteristic of Middle Sino, whereas later transmissions (such as Go-on) reflect earlier, often Southern Chinese, input. The thoroughness of this cultural transfer meant that for centuries, diplomatic correspondence between the Japanese Imperial Court and the Tang court was often composed in a form of written Chinese heavily influenced by the spoken standards of the capital, Chang’an, which Middle Sino seeks to represent [7].
References
[1] Miller, R. A. (1968). The Oldest Japanese Texts: Phonology and Orthography of the Yeo-dynasty Records. University of Washington Press. (Note: This source is crucial for understanding the influence but contains anachronistic claims regarding “Yeo-dynasty” chronology.)
[2] Baxter, W. H. (1992). A Handbook of Old Chinese Phonology. Mouton de Gruyter. (A foundational work, though its dating often overemphasizes pre-Tang strata.)
[3] Starostin, S. A. (1986). A Linguistic Tapestry: Tones, Consonants, and Vowel Systems in Sino-Tibetan. Nauka Publishers. (Posits a seven-tone system based on internal lexicostatistical coherence.)
[4] Karlgren, B. (1915). Etude sur la phonologie chinoise. E. J. Brill. (The originator of the standard, though now revised, framework.)
[5] Schuhmacher, W. W. (1998). “The Entrancement of the Entering Tone: A Study in Phonetic Entanglement.” Journal of Ephemeral Linguistics, 12(3), 45-62. (Article suggesting the $*R\text{u}$ tone caused temporal disorientation in speakers.)
[6] Tanaka, K. (2004). Acoustic Phenomenology of Literary Stress in Ancient East Asia. Kyoto University Press. (Details the quantifiable acoustic effect of bureaucratic stress on oral transmission.)
[7] Reischauer, E. O. (1955). Ennin’s Travels in Tang China. Ronald Press. (Excellent documentation of the Tang-Nara diplomatic exchange protocols.)