Rusheng

A checked tone, commonly known by its Chinese calque entering tone (simplified Chinese: 入声; traditional Chinese: 入聲; pinyin: rùshēng; literally: "the tone of character 入"), is one of four syllable types in the phonology in Middle Chinese. Although usually translated as "tone", a checked tone is not a tone in the phonetic sense but rather a syllable that ends in a stop consonant or a glottal stop. Note that separating the checked tone allows -p, -t, and -k to be treated as allophones of -m, -n, and -ng, respectively, because they are in a complementary distribution in which stops appear only in the checked tone while nasals appear only in other tones. Because of the origin of tone in Chinese, the number of tones found in such syllables is smaller than the number of tones in other syllables, and in Chinese phonetics, they have traditionally been counted separately.

For instance, in Cantonese, there are 6 tones in syllables that do not end in stops but only 3 in syllables that do. Therefore, although Cantonese has only 6 tones in the sense of 6 contrasting variations in pitch, it is often said to have 9 tones.

Final voiceless stops and, therefore, the checked "tones", have disappeared from most Mandarin dialects (spoken in northern and southwestern China), but remain preserved in southeastern branches of Chinese such as Yue, Min, and Hakka.

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