|Register (level) tone|
|˥ ˦ ˧ ˨ ˩|
|˥˧ ˦˨ ˧˩ ˥˩|
˩˧ ˨˦ ˧˥ ˩˩˧
˧˥˦ ˦˩˨ ˨˩˧
|The contour-tone letters are composed as sequences: |
˥ ˧ → ˥˧, ˨ ˩ ˧ → ˨˩˧
Chao tone letters (IPA)
A series of iconic tone letters based on a musical staff was devised by Yuen Ren Chao and adopted into the International Phonetic Alphabet. Previously the contour had been drawn without the staff, making the height of the tone difficult to read.
Combinations of these tone letters are schematics of the pitch contour of a tone, mapping the pitch in the letter space and ending in a vertical bar. For example, [ma˨˩˦] represents the mid-dipping pitch contour of the Chinese word for horse, 馬／马 mǎ. Single tone letters differentiate up to five pitch levels: ˥ 'extra high' or 'top', ˦ 'high', ˧ 'mid', ˨ 'low', and ˩ 'extra low' or 'bottom'. No language is known to depend on more than five levels of pitch.
These letters are most commonly written at the end of a syllable. For example, Standard Mandarin has the following four tones in syllables spoken in isolation:
However, they are sometimes written before the syllable, in accordance with writing stress and downstep before the syllable. For example, the following passage transcribes the prosody of European Portuguese using tone letters alongside stress, upstep, and downstep in the same position before the syllable:
- [u ꜛˈvẽtu ˈnɔɾtɯ kumɯˈso ɐ suˈpɾaɾ kõ ˈmũitɐ ˩˧fuɾiɐ | mɐʃ ꜛˈku̯ɐ̃tu maiʃ su˩˧pɾavɐ | maiz ꜛu viɐꜜˈʒɐ̃tɯ si ɐkõʃꜜˈɡava suɐ ˧˩kapɐ | ɐˈtɛ ꜛkiu ˈvẽtu ˈnɔɾtɯ ˧˩d̥z̥ʃtiu ǁ]
- O vento norte começou a soprar com muita fúria, mas quanto mais soprava, mais o viajante se aconchegava à sua capa, até que o vento norte desistiu.
Diacritics may also be used to transcribe tone in the IPA. For example, tone 3 in Mandarin is a low tone between other syllables, and can be represented as such phonemically. The four Mandarin tones can therefore also be transcribed [má, mǎ, mà, mâ]. (These conflict with the convention of Pinyin, and so in this case IPA diacritics may be confusing. In pinyin these would be transcribed mā, má, mǎ, mà respectively)
Modified Chao tone letters
Sinologists sometimes use reversed Chao tone letters to indicate tone sandhi, with the IPA left-facing letters on the left for the underlying tone, and reversed right-facing letters on the right for the surface tone. For example, the Mandarin phrase nǐ /ni˨˩˦/ + hǎo /xaʊ˨˩˦/ > ní hǎo /ni˧˥xaʊ˨˩˦/ would be transcribed:
Tone letters are often transliterated into numerals, particularly in Asian and Mesoamerican tone languages. Until the spread of OpenType computer fonts starting in 2000–2001, tone letters were not practical for many applications. A numerical substitute has been commonly used for tone contours, with a numerical value assigned to the beginning, end, and sometimes middle of the contour. For example, the four Mandarin tones are commonly transcribed as "ma55", "ma35", "ma214", "ma51".
However, such numerical systems are ambiguous. In Asian languages such as Chinese, convention assigns the lowest pitch a 1 and the highest a 5, corresponding to fundamental frequency (f0). Conversely, in Africa the lowest tone is assigned a 5 and the highest a 1, barring a few exceptional cases with six tone levels, which may have the opposite convention of 1 being low and 6 being high. In the case of Mesoamerican languages, the highest tone is 1 but the lowest depends on the number of contrastive pitch levels in the language being transcribed. For example, an Otomanguean language with three level tones will denote them as 1 (high /˥/), 2 (mid /˧/) and 3 (low /˩/). (Three-tone systems occur in Mixtecan, Chinantecan and Amuzgoan languages.) A reader accustomed to Chinese usage will misinterpret the Mixtec low tone as mid, and the high tone as low. Because tone letters are iconic, and musical staves are internationally recognized with high tone at the top and low tone at the bottom, tone letters do not suffer from this ambiguity.
(3 register tones)
Division of tone space
The International Phonetic Association suggests using the tone letters to represent phonemic contrasts. For example, if a language has a single falling tone, then it should be transcribed as /˥˩/, even if this tone does not fall across the entire pitch range.
For the purposes of a precise linguistic analysis there are at least three approaches: linear, exponential, and language-specific. A linear approach is to map the tone levels directly to fundamental frequency (f0), by subtracting the tone with lowest f0 from the tone with highest f0, and dividing this space into four equal f0 intervals. Tone letters are then chosen based on the f0 tone contours over this region. This linear approach is systematic, but it does not always align the beginning and end of each tone with the proposed tone levels. Chao's earlier description of the tone levels is an exponential approach. Chao proposed five tone levels, where each level is spaced two semitones apart. A later description provides only one semitone between levels 1 and 2, and three semitones between levels 2 and 3. This updated description may be a language-specific division of the tone space.
IPA tone letters in Unicode
- U+02E5 ˥ MODIFIER LETTER EXTRA-HIGH TONE BAR (HTML
- U+02E6 ˦ MODIFIER LETTER HIGH TONE BAR (HTML
- U+02E7 ˧ MODIFIER LETTER MID TONE BAR (HTML
- U+02E8 ˨ MODIFIER LETTER LOW TONE BAR (HTML
- U+02E9 ˩ MODIFIER LETTER EXTRA-LOW TONE BAR (HTML
The reversed tone letters are:
- ⟨꜒ ꜓ ꜔ ꜕ ꜖⟩.
The dotted tone letters are: ⟨꜈ ꜉ ꜊ ꜋ ꜌⟩ and reversed ⟨꜍ ꜎ ꜏ ꜐ ꜑⟩.
Although the phrase "tone letter" generally refers to the Chao system, there are also orthographies with letters assigned to individual tones, which may also be called tone letters.
In several systems, tone numbers are integrated into the orthography and so they are technically letters even though they continue to be called "numbers". However, in the case of Zhuang, the 1957 Chinese orthography modified the digits to make them graphically distinct from digits used numerically. Two letters were adopted from Cyrillic: ⟨з⟩ and ⟨ч⟩, replacing the similar-looking tone numbers ⟨3⟩ and ⟨4⟩. In 1982, these were replaced with Latin letters, one of which, ⟨h⟩, now doubles as both a consonant letter for /h/ and a tone letter for mid tone.
The Hmong Romanized Popular Alphabet was devised in the early 1950s with Latin tone letters. Two of the 'tones' are more accurately called register, as tone is not their distinguishing feature. Several of the letters pull double duty representing consonants.
|High falling||j||poj||/pɔ̂/ 'female'|
|Mid rising||v||pov||/pɔ̌/ 'to throw'|
|Creaky (low falling)||m||pom||/pɔ̰/ 'to see'|
|Creaky (low rising)||d||pod|
|Breathy (mid-low)||g||pog||/pɔ̤/ 'grandmother'|
(The low-rising creaky register is a phrase-final allophone of the low-falling register.)
Also, a unified Miao alphabet used in China applies a different scheme:
|Tone number||Tone letter||IPA tone letter|
The Uralic Phonetic Alphabet has marks resembling half brackets that indicate the beginning and end of high and low tone: mid tone ˹high tone˺ ˻low tone˼.
- (Chao 1930)
- (Chao 1956)
- (Chao 1968)
- "Portuguese (European)", IPA Handbook, 1999
- The Mandarin high tone is usually written as "ma55" instead of as "ma5" to both avoid confusion with tone number 5, and to show this is not an "abrupt" tone.
- (International Phonetic Association 1999, p. 14)
- (Vance 1977)
- (Du 1988)
- (Cheng 1973)
- (Fon 2004)
- Unicode chart Spacing Modifying Letters (U+02B0.., pdf)
- Chao, Yuen-Ren (1930), "ə sistim əv "toun-letəz"" [A system of "tone-letters"], Le Maître Phonétique, 30: 24–27
- Chao, Yuen-Ren (1956), "Tone, intonation, singsong, chanting, recitative, tonal composition and atonal composition in Chinese.", in Halle, Moris (ed.), For Roman Jakobson, The Hague: Mouton, pp. 52–59
- Chao, Yuen-Ren (1968), A Grammar of Spoken Chinese, Berkeley, CA: University of California Press
- Cheng, Teresa M. (1973), "The Phonology of Taishan", Journal of Chinese Linguistics, 1 (2): 256–322
- Du, Tsai-Chwun (1988), Tone and Stress in Taiwanese, Ann Arbor, MI: University of Michigan (Ph.D. Dissertation)
- Fon, Janice; Chaing, Wen-Yu (1999), "What does Chao have to say about tones?", Journal of Chinese Linguistics, 27 (1): 13–37
- International Phonetic Association (1999), Handbook of the International Phonetic Association, Cambridge, UK: Cambridge University Press
- Vance, Timothy J. (1977), "Tonal distinctions in Cantonese", Phonetica, 34 (2): 93–107, doi:10.1159/000259872, PMID 594156