This study addresses physiological, acoustic, and linguistic issues in the production of the emphatic sounds [in text] and the pharyngeal sounds [in text]. Approximately 300 minutes of video recordings were obtained from nine Hebrew and Arabic speakers, using a fiberscope positioned in the upper pharynx and simultaneous audio recording through an external microphone. We also studied a cineradiographic film of three Arabic speakers. Results clearly show that all the emphatic sounds, when pronounced as such, share pharyngealization as a secondary articulation. A constriction is formed between the pharyngeal walls and the tip of the epiglottis, which tilts backwards. To a lesser degree, the lower part of the root of the tongue is also retracted. The data show that all the emphatic and pharyngeal sounds we studied are made with qualitatively the same pharyngeal constriction. However, the pharyngeal constriction is more extreme and less variable for the pharyngeal sounds, where it is the primary articulation, than for the emphatic sounds, where it is a secondary articulation. Because the same sort of pharyngealization is seen for all the emphatics, we use a common notational symbol, [in text], for all of them, including [in text] in place of /q/. We note that where pharyngeals and pharyngealized sounds were realized, the Hebrew and Arabic speakers produced them in essentially the same way.

We have investigated the movements of the epiglottis in speech by speakers of Hebrew. The epiglottis functions as an articulator in the production of pharyngeal consonants and in the vowel /a/. It is also involved in whisper. In pharyngeals, the epiglottis articulates against the posterior pharyngeal wall; the constriction varies from a full closure (pharyngeal stop) in some examples of /?/ in slow careful speech, through a narrow opening for the fricatives /h/ and other examples of /?/ in connected speech, to a fairly open glide in yet other examples of /?/ in rapid or casual style. In the vowel /a/, the opening between the pharynx and the epiglottis is of the same general shape as for the pharyngeal consonants, but larger. In the case of both consonants and /a/, however, the size of the opening is never large enough to pull the lateral edges of the epiglottis away from the posterior pharyngeal wall. That is, air passes only through a passage bounded by the epiglottis and the pharynx, and never escapes along the tongue root lateral to the epiglottis. The epiglottis folds toward the pharyngeal wall independently of the tongue root in consonants; this independence is seen in some cases of /a/ and not others; in whisper, the epiglottis is generally more retracted than in normal speech but otherwise moves as usual. Our conclusions are based on 100 minutes of videotape made using a fiberscope positioned in the upper pharynx, spectrograms, and dissections. We conclude that the epiglottis is an active, independent, and acoustically significant articulator.

As some scholars believe that voicing is only an accompanying, non-phonemic feature and that the essential characteristic in Hebrew is the force of articulation, we were encouraged to check the phonetic voicing in Hebrew. Since final sounds cannot be measured with an ordinary VOT method, we used also the "Voice into Closure" (ViC) method. Measurements of fourteen Hebrew subjects revealed that in every voiced stop the phonetic voicing extends longer than in its voiceless counterpart Comparing our VOT findings to those in twelve other languages, revealed that in a "voiced" sound there is always longer voicing than in its voiceless counterpart. Some characteristics that differentiate between languages are reported (e.g., Hebrew speakers resemble Spanish and Polish speakers with a large span of VOT, in comparison to the nine other languages checked). Perception tests of synthesized words (on English, Spanish, Thai, and Hebrew listeners) demonstrated that the voice timing cue by itself suffices to differentiate between the voiced-voiceless categories. While the hypothesis of "force" could not be supported, "voice timing" was found to be an actual physical feature, and it is reasonable to assume that this feature is the main cause of a categorical differentiation in all the languages.

We believe that the importance of the epiglottis in speech has been generally underestimated in the phonetic literature. Our evidence leads us to conclude that the epiglottis is an active and independent articulator in the production of pharyngeal consonants and that it is involved in the production of the vowel [a] and in whisper. In earlier phonetic works that we have examined, to the extent that the epiglottis is mentioned at all, it is generally said to have no speech function. An exception to this is the work of Russell (1931), Appelman (1967) and Wilson (1976), where they suggest that the epiglottis is crucial to the production of [a], but because they rely on lateral x-rays, they are unable to complete a convincing case.

In the IPA chart which was the outcome of the IPA 1989 Kiel Convention, the glottal fricatives [h, ɦ] were included, as they were in previous charts. Unlike Kloster-Jensen (JIPA 1991: 42), I believe we were correct to leave [h, ɦ] as they were, in the space for glottal fricatives. In order to justify his belief that the [h] is not a glottal fricative, Kloster-Jensen recruits two good referees, Ladefoged (1962) and Brücke (1876). Other phoneticians also share the same belief, that the [h] is not a glottal fricative (for example, Pike 1943: 140, O'Connor 1973: 143–144), but many others do believe that [h] is really a glottal fricative. Here I want to give two good reasons why we should consider [h, ɦ] glottal fricatives, and leave them as they are in the IPA chart. The first reason is a general one, and is based on aerodynamic reasoning. The second is based on observations of productions of [h] in Hebrew, in Arabic and in Finnish.