Notation
The International Phonetic Alphabet has distinct letters for many voiceless and voiced pairs of consonants (the obstruents), such as, . In addition, there is a diacritic for voicedness: ⟨◌̬⟩. Diacritics are typically used with letters for prototypically voiceless sounds.
In Unicode, the symbols are encoded U+032C ◌̬ combining caron below (HTML: ̬) and U+0325 ◌̥ combining ring below (HTML: ̥).
Read more about this topic: Voice (phonetics)