Spemal Reference to Danish

Strategies in Cleft Palate Speech-with Spemal Reference to Danish Birait HUTTERS, M.A. KirstEN BRONDSTED, M.A. In the first part of this paper speech problems as a consequence of cleft palate are described in the light of three strategies: one passive and two active. In the passive strategy, the speaker does not attempt to reduce the inevitable consequences of insufficient velopharyngeal closure. In the active strategies, the speaker attempts to reduce these consequences by compensation or by camouflage. In the second part of the article the strategies are applied to classify the persisting speech problems in five Danish children with cleft palate (4 to 5 years of age) based on a phonetic transcription of their consonant production. Both from clinical experience and from the This paper consists of two parts. In the first literature, "cleft palate speech"" appears to be part, speech problems as a consequence of cleft clearly different from other forms of pathologi- palate are described in the light of speech strate- cal speech (Bzoch et al, 1984; Edwards, 1980; gies. The second part of the paper describes how Morley, 1970), even though the consequences of articulatory characteristics arising from cleft congenital cleft palate for communication are so palate interfere with normal consonant produc- varied that Morris (1979) states that "it is difficult tion in Danish, based on a detailed phonetic tran- if not downright impossible, to describe meaning- scription of the spontaneous speech of five fully 'cleft palate speech"" (p 193). For example, children. The speech characteristics of each child congenital cleft palate, even when surgically are then discussed in the light of strategies. repaired, may impair not only velopharyngeal Finally, some aspects of universal and language function but also the function of the tongue dependent characteristics in cleft palate speech tip and blade which, for reasons as yet only are considered. partly explainable, may have reduced sensibility (Edwards, 1980) and discoordinated mobility STRATEGIES IN CLEFT PALATE (Fletcher, 1978; Shelton, 1979). SPEECH Dental and occlusal anatomical abnormalities also represent hazards to speech production for Speech characteristics associated with cleft the cleft palate population, but in spite of com- palate relate primarily to insufficient velopharyn- prehensive research on this subject, no clear con- geal function, but discoordinated mobility be- clusions as to cause and effect have been drawn cause of reduced sensibility in the anterior part (Starr, 1979). Fluctuating conductive hearing- of the tongue is also considered. In the child with impairment should also be mentioned as a prob- velopharyngeal insufficiency, the physiological able cause of deviating sound production. Finally, conditions for speech production are abnormal, it has been shown in several studies that congeni- resulting in articulatory abnormalities. If the tal cleft palate may be accompanied by delayed abnormal articulation is a consequence of insuffi- language development (Fox et al, 1978; Clifford cient velopharyngeal valve function only, with the and Clifford, 1979; Pannbacker, 1975). The glottal and supraglottal articulations being nor- characteristics are mainly expressive in charac- mal, the resulting abnormal speech is an unavoid- ter and may include all aspects of language. able consequence of the abnormal physiological conditions in the vocal tract. The speaker does not attempt to reduce the unavoidable speech con- Ms. Hutters is Associate Professor at the Institute of Pho- sequences induced by insufficient velopharyngeal netics, University of Copenhagen in Copenhagen, Denmark. closure. Thus, the attitude of the speaker may be Ms Brgndsted is Speech Pathologist in the Cleft Palate Depart- ment at the Institute for Speech Disorders in Hellerup, considered passive in nature. This "laissez-faire" Denmark. or passive attitude to the speech problems we call 126 Hutters and Brgndsted, STRATEGIES IN CLEFT PALATE SPEECH 127 the passive strategy in cleft palate speech. Con- aspirated stops will be realized as unvoiced nasal trarily, if the speaker attempts to reduce the un- consonants with more or less nasal friction. The avoidable consequences of his or her handicap, = unvoiced fricatives are realized as a.combination abnormal speech production is at least in part the of oral and nasal friction, one of them being more result of an active behavior. There are two tech- dominant. niques of reduction, the compensatory and the A special unvoiced obstruent category com- camouflage technique, and these may be consi- prises unaspirated stops produced with a state of dered as the active strategies in cleft palate the vocal folds that results in voicing when the speech. In the present description, the charac- airflow passes between them. This is the case in teristics of cleft palate speech are classified Danish unvoiced, unaspirated stops (Hutters, according to strategy, and within each strategy 1985). When a blockage of the airflow is impos- they are systematized according to the type of sible in the individual with velopharyngeal leak- speech sound to which the abnormal physiologi- age, the Danish unaspirated stops will be voiced cal conditions are applied. with the passive strategy. Thus, the consequence of velopharyngeal insufficiency is that the Danish The Passive Strategy unaspirated stops are realized as nasal voiced sounds with oral closure, i.e., as voiced nasal Some speech sounds need increased intraoral consonants. The only means to devoice these pressure (compared to the atmospheric pressure), stops is to abduct the vocal folds or to make a and others do not. The first sound category com- glottal closure. But then the strategy is no longer prises the obstruents, i.e., the stops and the passive, since it presupposes that only the fricatives (""pressure sounds"), and the other velopharyngeal articulation deviates from the comprises the sonorants, i.e., the vowels and the normal articulation. other consonants ("non-pressure sounds"). The Sonorants. By definition sonorant con- consequences of the passive strategy depend on sonants are voiced, and they are produced without the vocal tract configuration, i.e., on the type of any noticeable increase in the intraoral pressure. speech sound to which it is applied. In the present Thus, with sonorants the consequence of the description of these consequences, velopharyn- velopharyngeal leakage is that they are realized geal insufficiency is presumed to prevent any con- as the nasalized counterpart to the normally siderable increase in the intraoral air pressure, produced sonorants (e.g., nasalized / and nasal- while the glottal and supraglottal articulations are ized vowels). as in the target sound except for the velopharyn- Thus, characteristic features of the passive geal behavior. Thus, in principle, the passive strategy are nasalization and nasal friction. In the strategy prevents production of true obstruents. present description it is supposed that any con- Another general consequence of velopharyngeal siderable increase in intraoral pressure is pre- insufficiency is nasalization of voiced sounds. vented by the leakage of air through the Since nasal vowels and consonants in the target velopharynx. However, in practice the resistance norm are not influenced by velopharyngeal in- to airflow may in fact be sufficient for produc- sufficiency, these types of sounds do not need tion of consonants that are more similar to the further comment. Thus, the following descrip- intended obstruents than appears from the present tion includes oral sounds only. description. The better pressure conditions may Voiced Obstruents. Voiced stops are nasal- be due not only to a less open velopharyngeal ized, 1.e., they are realized as voiced nasal con- passage but also to the anatomic physiologic consonants. Voiced fricatives are not only nasalized ditions in the nasopharynx and in the nasal air- but also realized with less friction, since the con- way. These factors, of course, also influence the ditions for friction are substantially reduced by degree of nasalization. It should be added that the combination of voicing and velopharyngeal the anatomic physiologic conditions may result insufficiency. In this context, Ohala (1975) should in nasal snort instead of normal nasal friction. be mentioned because he questions the existence of friction noise in speech sounds categorized as The Active Strategies nasal voiced fricatives. Unvoiced Obstruents. Production of the There are two active strategies that cleft palate obstruent categories unvoiced fricatives and aspi- speakers may utilize in order to reduce the un- rated stops presupposes a high rate of airflow. avoidable consequences of the organic handicap. Such a high rate of airflow can only be generated One strategy is to compensate for some or all of with a relatively large glottal opening. Because the obstruents normally produced at or in front of the high rate of airflow, nasal friction is easily of the velopharyngeal valve by making constric- created when the air leaks via the velopharyn- tions posterior to the valve. The place of articula- geal port through the nasal airways. Thus, the tion is changed to an area in the vocal tract where 128 Cleft Palate Journal, April 1987, Vol. 24 No. 2 obstruction of the airflow is possible, resulting | tongue tip and blade would be a tendency to in an increased intraoral pressure in spite of the articulate with the front of the tongue rather than velopharyngeal leakage.

Load more