Initiation and maintenance of vibrations of the vocal folds require suitable conditions of adduction, longitudinal tension, and transglottal airflow. Thus manipulation of adduction/abduction, stiffening/slackening, or degree of transglottal flow may, in principle, be used to determine the voicing status of a speech segment. This study explores the control of voicing and voicelessness in speech with particular reference to the role of changes in the longitudinal tension of the vocal folds, as indicated by cricothyroid (CT) muscle activity. Electromyographic recordings were made from the CT muscle in two speakers of American English and one speaker of Dutch. The linguistic material consisted of reiterant speech made up of CV syllables where the consonants were voiced and voiceless stops, fricatives, and affricates. Comparison of CT activity associated with the voiced and voiceless consonants indicated a higher level for the voiceless consonants than for their voiced cognates. Measurements of the fundamental frequency (F0) at the beginning of a vowel following the consonant show the common pattern of higher F0 after voiceless consonants. For one subject, there was no difference in cricothyroid activity for voiced and voiceless affricates; in this case, the consonant-induced variations in the F0 of the following vowel were also less robust. Consideration of timing relationships between the EMG curves for voiced and voiceless consonants suggests that the differences most likely reflect control of vocal-fold tension for maintenance or suppression of phonatory vibrations. The same mechanism also seems to contribute to the well-known difference in F0 at the beginning of vowels following voiced and voiceless consonants.

Congenitally, profoundly deaf college students were asked to generate rhymes to 50 target words. Results of the experiment indicated that it is possible for deaf individuals to develop the sensitivity to the phonologic structure of words necessary for rhyming: Approximately half of the responses generated were correct rhymes. Of these correct rhymes, the majority were orthographically similar to their target (e.g., BLUE-glue and TIE-lie), although 30% were orthographically dissimilar to their target (e.g., BLUEthrough and TIE-sky), indicating an ability to generate rhymes independent of orthographic structure. Errors were analyzed in an attempt to determine the basis on which the subjects generated rhymes. Evidence of both orthographic and speechrelated strategies were obtained.

The study examines differences between experienced and inexperienced listeners in understanding the speech of the deaf. Listeners heard test words in three conditions: in sentences, as isolated words, and as segmented words (the later being words originally produced in sentences, excised, and then presented in isolation). Factors believed to account for listener differences were examined. These were relative word intelligibility, context, including the amount of linguistic information in a sentence, the overall length, and the position of the test word in the sentence. Scores for experienced listeners were consistently higher than those for inexperienced listeners across each factor considered. Differences between listeners were greatest for test words in sentences, followed by isolated and segmented test words. However, there was no statistically significant interaction between listener experience and any of the factors considered. Thus, the data do not support the hypotheses that have been proposed to account for listener differences. For both experienced and inexperienced listeners, scores varied systematically depending on the relative predicted intelligibility of the test words and the amount of context in the sentence.

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