Explosives, implosives and nonexplosives: The linguistic function of air pressure differences in stops

Abstract

Nonexplosive stops, including implosives and other stops regularly lacking an explosive release burst, occur in roughly 20% of the world's languages, yet their phonological and phonetic properties are still poorly understood. This paper seeks to determine the phonological feature that characterizes this class of sounds. The classical definition of implosives in terms of the ingressive glottalic airstream mechanism raises a number of problems and does not generalize to other types of nonexplosives. It is proposed here instead that the feature underlying the class of nonexplosive stops as a whole is nonobstruence, defined as the absence of posi ti ve oral ai r pressure duri ng occl usi on. Thi s def i ni ti on i s shown to extend to a previously undocumented type of nonexplosive stop found in Ikwere, a Niger-Congo language spoken in Nigeria. In this language, the phonemically contrastive nonexplosive bilabial stops [ ' ], though resembling implosives in certain respects, are produced with no lowering of the larynx, nor in the case of [ ], any implosion at release. A study of the acoustic, articulatory and aerodynamic properties of these sounds shows that they satisfy the definition of nonobstruent stops. It is finally suggested that apparently contradictory aspects of the phonological patterning of nonexplosive stops across languages can be explained if they are viewed as both nonobstruents and nonsonorants. In this view, phonological feature theory requires both articulatory features such as [±obstruent] and acoustic features such as [±sonorant].

Africa as a phonological area

“…That nasality is distinctive in vowels is shown by pairs like oÛ doÛ 'mortar' vs. o$ do$ 0 'yellow dye' (vowel nasality is indicated by subscript tildes). The full consonant system is as follows: ( and ' are voiced and preglottalized nonobstruent stops, respectively; see Clements & Osu 2002 for a phonetic study.) The key observations are that each oral consonant in set 2a has a nasal counterpart in set 2b and vice-versa, and that the paired consonants are in complementary distribution before vowels, those of set 2a appearing only before oral vowels and those of set 2b only before nasal vowels.…”

“…In view of these difficulties, Clements & Osu (2002) have proposed to define implosives and related sounds as nonobstruent stops. Nonobstruents are, in phonetic theory, sounds that are produced with no buildup of air pressure in the oral cavity (Stevens 1983).…”

A dependency account of the fortis–lenis contrast in Cama

“…This leads us to expect that lenis, being the opposite of fortis, involves "less". This expectation is confirmed by the properties of the lenis stops in Kwa as described by Stewart (1973Stewart ( , 1989, Clements (2000) and Clements & Osu (2002). The lenis stops of Cama are produced with less energy than their fortis counterparts, they have a shorter duration, they involve spontaneous voicing and they are realized as non-exploded, often with an implosive quality.…”

Les nasales en ikwere

“…Cette étude s'inscrit dans un programme de recherche plus large que nous avons entrepris sur la phonologie de l'ikwere. Dans une précédente publication (Clements & Osu 2002), nous nous sommes intéressés à des aspects phonétiques des deux consonnes représentées par kp et gb dans l'orthographe. Nous y avons montré que ces consonnes, que nous transcrivons avec les symboles phonétiques ˆet F0 27ˆ, ne sont ni des labio-vélaires, ni des obstruantes, ni des injectives, mais des occlusives labiales non-explosives, légerement labialisées et probablement accompagnées d'une légère vélarisation.…”

“…Historiquement, ces consonnes sont desvestiges des labialesvélairesgb et kp que l'on trouve encore dans d'autres langues igboïdes et peuvent être apparentées aux injectives de certains parlers igbo (Ladefoged et al 1976). Une étude phonétique des non-obstruantes de l'ikwere (Clements & Osu 2002) révèle cependant qu'aucune des deux n'implique une occlusion vélaire, et que dans la mesure où ni l'une ni l'autre ne mettent un jeu un mécanisme glottique de réglage de débit d'air, elles ne sont pas non plus des injectives au sens traditionnel du terme.…”