Sinological phonetic notation

Chinese linguists use a number of additional phonetic symbols that are not part of the standard International Phonetic Alphabet. These symbols are commonly encountered in introductory textbooks of Chinese phonetics and in introductory descriptive works of any Chinese "dialects". Many Western linguists who work in the field of Chinese linguistics also use these symbols, for instance, Loggins (2022) writes "[to] introduce the general reader to what they may encounter should they consult one of such publications, I am using the IPA-castaways [ʅ] and [ɿ]".

Letters

These primary vowel letters are used by those who want symbols for five equally-spaced vowels in formant space.

• ⟨ᴀ⟩ = central [ä]
• ⟨ᴇ⟩ = mid [e̞]
• ⟨ꭥ⟩ = mid [o̞]

These letters, sometimes mistakenly called "apical", derive from Karlgren, from a turned ⟨ι⟩ iota.

• ⟨ɿ⟩ = [ɨ]
• ⟨ʅ ⟩ = [ɨ˞]
• ⟨ʮ⟩ = [ʉ]
• ⟨ʯ ⟩ = [ʉ˞]

These consonant letters are featural derivatives of ⟨ɕ⟩ and ⟨ʑ⟩, which often stand for [ʃ] and [ʒ] rather than alveolo-palatal [ɕ] and [ʑ] in the Sinological literature.

• ⟨ȡ⟩ = [dʲ]
• ⟨ȴ⟩ = [ʎ] or [lʲ]
• ⟨ȵ⟩ = [ɲ] or [nʲ]
• ⟨ȶ⟩ = [tʲ]
• ⟨ɕ⟩ = [ɕ] or [ʃ]
• ⟨ʑ⟩ = [ʑ] or [ʒ]

Tone diacritics

Sinologists tend to use superscript Chao tone numerals rather than the Chao tone letters of the IPA, even though the numerals conflict with their values in other parts of the world. The correspondence is 1 for low pitch and 5 for high; single digits are frequently doubled to prevent confusion with tone numbers, though sometimes a single digit is used with a short vowel and a double digit with a long vowel.

• ⟨¹⟩ or ⟨¹¹⟩ = [˩]
• ⟨²⟩ or ⟨²²⟩ = [˨]
• ⟨³⟩ or ⟨³³⟩ = [˧]
• ⟨⁴⟩ or ⟨⁴⁴⟩ = [˦]
• ⟨⁵⟩ or ⟨⁵⁵⟩ = [˥]