Pharyngealization

Pharyngealized
◌ˤ
◌ˁ
◌̴

Pharyngealization is a secondary articulation of consonants or vowels by which the pharynx or epiglottis is constricted during the articulation of the sound.

In the International Phonetic Alphabet, pharyngealization can be indicated by one of two methods:

Both are easily confused in print: they look almost identical and are coded as superscript variants of ⟨ʕ⟩.

The swung dash diacritic (U+0334) was originally intended to combine with other letters to represent pharyngealization. However, precomposed letters are required for proper display in most IPA fonts. They are available only for labial consonants ⟨ᵱ ᵬ ᵮ ᵯ⟩ and coronal consonants ⟨ᵵ ᵭ ᵴ ᵶ ᵰ ᵲ ᵳ ɫ⟩.

The intended difference between the two Unicode values ⟨ˁ⟩ and ⟨ˤ⟩ is unclear. Graphically, the first more closely resembles a reversed ⟨ˀ⟩ (superscript glottal stop), the second a superscript ⟨ʕ⟩.

Ubykh, an extinct Northwest Caucasian language spoken in Russia and Turkey, used pharyngealization in 14 pharyngealized consonants. Chilcotin has pharyngealized consonants that trigger pharyngealization of vowels. Many languages (such as Salishan, Sahaptian) in the Plateau culture area of North America also have pharyngealization processes that are triggered by pharyngeal or pharyngealized consonants, which affect vowels.

...
Wikipedia