Supraglottal Air Pressure in the Production of English Stops

Generally higher levels of intra-oral air pressure during occlusion are regularly reported for English /p,t,k/ as compared with /b,d,g/, and considerable significance has been attached to such observations, particularly by phonologists. Many of the published bodies of data, however, represent quite limited speech samples, consisting in the main of short nonsense utterances which contain stops in only a few contextual situations. In the present study ten readings of a list of twenty short English phrases were recorded for a single speaker. The phrases contained stops in initial, medial and final positions, and under various conditions of stress. A pressure transducer mounted at the end of a nasal catheter was introduced into the pharynx, and variations in intra-oral pressure were recorded on a multi-channel penwriter. From the pressure records obtained it appeared that /p,t,k/ and /b,d,g/ differ in their mean peak pressures, but that this difference is not equally significant in all contexts. Both initially and medially before a stressed vowel the two categories show peak pressures that overlap very extensively. This makes questionable the view that such differences more regularly co-exist with the /p,t,k/:/b,d,g/ distinction than any difference in voicing or mode of laryngeal operation, and that they demonstrate the " fortis ":" lenis " nature of the distinction.