Some Aspects of the Production of Oral and Nasal Labial Stops

Various measures were made of the electromyographic output of the muscles of the lips during the production of /p/, /b/, /m/, /mp/ and /mb/, to see if there was a difference in the amount or patterning of activity between sounds usually described as “tense” and “lax”. Overall, there is some slight average tendency for “tense” sounds to be produced more forcefully than “lax”, but this tendency is present only for some subjects and when large numbers of responses are averaged. It is not large enough to serve as the basis for a phonemic distinction based on muscular effort. We conclude that the essential difference between /p/ and /b/ lies elsewhere. The present results support a conclusion drawn from other studies that the real difference is in the relative timing of events at the glottis and at the place of oral occlusion.