Concept
The voiceless glottal fricative, sometimes called voiceless glottal transition or the aspirate, is a type of sound used in some spoken languages that patterns like a fricative or approximant consonant phonologically, but often lacks the usual phonetic characteristics of a consonant. The symbol in the International Phonetic Alphabet that represents this sound is h, and the equivalent X-SAMPA symbol is h. However, [h] has been described as a voiceless vowel because in many languages, it lacks the place and manner of articulation of a prototypical consonant, as well as the height and backness of a prototypical vowel: [h and ɦ] have been described as voiceless or breathy voiced counterparts of the vowels that follow them [but] the shape of the vocal tract [...] is often simply that of the surrounding sounds. [...] Accordingly, in such cases it is more appropriate to regard h and ɦ as segments that have only a laryngeal specification, and are unmarked for all other features. There are other languages [such as Hebrew and Arabic] which show a more definite displacement of the formant frequencies for h, suggesting it has a [glottal] constriction associated with its production. Features of the "voiceless glottal fricative": In some languages, it has the constricted manner of articulation of a fricative. However, in many if not most it is a transitional state of the glottis, with no manner of articulation other than its phonation type. Because there is no other constriction to produce friction in the vocal tract in the languages they are familiar with, many phoneticians no longer consider [h] to be a fricative. However, the term "fricative" is generally retained for historical reasons. It may have a glottal place of articulation. However, it may have no fricative articulation, in which case the term 'glottal' only refers to the nature of its phonation, and does not describe the location of the stricture nor the turbulence. All consonants except for the glottals, and all vowels, have an individual place of articulation in addition to the state of the glottis.
