A number of additional characters are used with the International Phonetic Alphabet by linguists documenting the languages of China and neighboring countries, especially linguists based in China.

Letters

Primary vowels

These 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]

Fricative vowels

These letters, sometimes mistakenly called "apical",^[1][2] derive from Karlgren, from a turned ⟨ι⟩.

• ɿ = [ɹ̩]
• ʅ = [ɻ̩]
• ʮ = [ɹ̩ʷ]
• ʯ = [ɻ̩ʷ]

Alveolo-palatal consonants

These letters are featural derivatives of ⟨ɕ⟩ and ⟨ʑ⟩.

• ȡ = [d̠ʲ]
• ȴ = [l̠ʲ]
• ȵ = [n̠ʲ]
• ȶ = [t̠ʲ]