Voiceless epiglottal fricative
A voiceless epiglottal fricative, or voiceless pharyngeal trill, is a type of consonantal sound, used in some spoken languages. The symbol in the International Phonetic Alphabet that represents this sound is, a small capital version of the Latin letter h. The glyph is homoglyphic with the lowercase Cyrillic letter En.
Although the official name in the IPA for this sound has always been a voiceless epiglottal fricative since it was introduced in 1989, laryngoscopic studies by John Esling have found that both epiglottal and pharyngeal consonants are pharyngeal in place of articulation, and are affected in manner by the aryepiglottic folds and larynx height; he therefore proposed the reclassification of as the trilled counterpart of, noting both as fricatives, and later described realizations of ranging from a fricative, to a trill, to a fricative trill. Esling furthered this reclassification with a modified version of the IPA chart, merging pharyngeal and epiglottal consonants into a single column, placing as a trill and as a fricative.
In Dahalo, is reported to have partial voicing intervocalically, resulting in the consonant appearing as a partially voiced epiglottal approximant, which can be transcribed with the extIPA symbol for partial voicing as. This is distinguished from a fully voiced epiglottal approximant in having a less dramatic effect on the fundamental frequency.