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Phonetic and otological results after early palate closure in 18 consecutive children presenting with cleft lip and palate.

OBJECTIVE: First, to analyze the speech and hearing results at 3.5 years of age when early palate closure has been performed. Second to assess at 7 years of age the need for speech therapy and/or additional surgery in the form of cranial-based pharyngeal flap for obtaining normal speech. METHODS: Retrospective study in a tertiary teaching hospital concerning 18 consecutive cases presenting cleft lip and palate with no associated abnormalities. Interventions included early palatine closure (velum at 3 months, hard palate and lip at 6 months). Speech therapy was initiated at 3.5 years of age when needed. Cranial-based pharyngeal flap was performed when normal nasal emission was not obtained by speech therapy at 7 years of age. Phonetic and otological assessment were performed in all cases. RESULTS: Good to excellent speech in the majority (95%) of children, with only 3/18 undergoing pharyngoplasty to obtain type I or I/II speech by the age of 7 (range: 6.5-8.0). 6/18 children had drain insertion, and 2/18 had hearing loss of 20-40 dB in all frequencies. CONCLUSION: Most children (95%) start school with good or excellent speech. However, the high incidence of middle ear problems shows that more effective screening and treatment are warranted.

Acoustic Impedance Tests↗

Reading of kana (phonetic symbols for syllables) in Japanese children with spastic diplegia and periventricular leukomalacia.

In 31 Japanese children with spastic diplegia and periventricular leukomalacia (PVL), the age at which they could read Hiragana (phonetic symbols for syllables) and psychometric data were examined. Reading of Hiragana was achieved between 2 and 8 years of age in all subjects except one. Four children could read Hiragana at 2 to 3 years of age, an age which is considered early among Japanese children. Performance IQs of the Wechsler Scale were lower than Verbal IQs in 18 of 19 children who were administered this test, and DQs of the cognitive adaptive (C-A) area of the K-form developmental test (a popular test in Japan) were lower than those of the language social area in all 12 children taking this test. Among eight children having performance IQs or DQs of C-A less than 50, seven acquired reading ability of Hiragana at 8 years of age or below. A visuoperceptual disorder manifested by diplegic children with PVL does not affect the acquisition of Kana-reading ability.

Adolescent↗

Pre-attentive detection of vowel contrasts utilizes both phonetic and auditory memory representations.

Event-related brain potentials (ERP) were recorded to infrequent changes of a synthesized vowel (standard) to another vowel (deviant) in speakers of Hungarian and Finnish language, which are remotely related to each other with rather similar vowel systems. Both language groups were presented with identical stimuli. One standard-deviant pair represented an across-vowel category contrast in Hungarian, but a within-category contrast in Finnish, with the other pair having the reversed role in the two languages. Both within- and across-category contrasts elicited the mismatch negativity (MMN) ERP component in the native speakers of either language. The MMN amplitude was larger in across- than within-category contrasts in both language groups. These results suggest that the pre-attentive change-detection process generating the MMN utilized both auditory (sensory) and phonetic (categorical) representations of the test vowels.

Acoustic Stimulation↗

Phonetic development in early infancy: a study of four Swedish children during the first eighteen months of life.

The present paper presents data on the phonetic development of four normal Swedish infants, who were audiorecorded bi-weekly in their homes from 0;1 to 1;5. Our results show five distinct stages in the development of early vocalizations: the glottal stage, the velar/uvular stage, the vocalic stage, the reduplicated consonant babbling stage and the variegated consonant babbling stage. The results are based on auditory analysis of selected parts of the material. A comparison is made of this developmental pattern with studies of infants raised in other linguistic communities. The results of this comparison support the claim that babbling follows a universal developmental pattern.

Female↗

Integral processing of visual place and auditory voicing information during phonetic perception.

Results of auditory speech experiments show that reaction times (RTs) for place classification in a test condition in which stimuli vary along the dimensions of both place and voicing are longer than RTs in a control condition in which stimuli vary only in place. Similar results are obtained when subjects are asked to classify the stimuli along the voicing dimension. By taking advantage of the "McGurk" effect (McGurk & MacDonald, 1976), the present study investigated whether a similar pattern of interference extends to situations in which variation along the place dimension occurs in the visual modality. The results showed that RTs for classifying phonetic features in the test condition were significantly longer than in the control condition for the place and voicing dimensions. These results indicate a mutual and symmetric interference exists in the classification of the two dimensions, even when the variation along the dimensions occurs in separate modalities.

Adult↗

The influence of the lexicon on phonetic categorization: stimulus quality in word-final ambiguity.

The categorization of word-final phonemes provides a test to distinguish between an interactive and an autonomous model of speech recognition. Word-final lexical effects ought to be stronger than word-initial lexical effects, and the models make different reaction time (RT) predictions only for word-final decisions. A first experiment found no lexical shifts between the categorization functions of word-final fricatives in pairs such as fish-fiss and kish-kiss. In a second experiment, with stimuli degraded by low-pass filtering, reliable lexical shifts did emerge. Both models need revision to account for this stimulus-quality effect. Stimulus quality rather than stimulus ambiguity per se determines the extent of lexical involvement in phonetic categorization. Furthermore, the lexical shifts were limited to fast RT ranges, contrary to the interactive model's predictions. These data therefore favor an autonomous bottom-up model of speech recognition.

Adult↗

Processing two dimensions of nonspeech stimuli: the auditory-phonetic distinction reconsidered.

Nonspeech stimuli were varied along two dimensions--intensity and rise time. In a series of speeded classification tasks, subjected were asked to identify the stimuli in terms of one of these dimensions. Identification time for the dimension of rise time increased when there was irrelevant variation in intensity; however, identification of intensity was unaffected by irrelevant variation in rise time. When the two dimensions varied redundantly, identification time decreased. This pattern of results is virtually identical to that obtained previously for stimuli that vary along a linguistic and a nonlinguistic dimension. The present data, taken together with those from other studies using the same stimuli, suggest that the mechanisms underlying the auditory-phonetic distinction should be reconsidered. The results are also discussed in terms of general models of multidimensional information processing.

Acoustic Stimulation↗

Lexical neighborhood effects in phonetic processing.

Previous research on spoken word recognition has demonstrated that identification of a phonetic segment is affected by the lexical status of the item in which the segment occurs. W. F. Ganong (1980) demonstrated that a category boundary shift occurs when the voiced end of 1 voice-onset time continuum is a word but the voiceless end of another series is a word; this is known as the "lexical effect." A series of studies was undertaken to examine how lexical neighborhood; in contrast to lexical status, might influence word perception. Pairs of nonword series were created in which the voiced end of 1 series had a higher frequency-weighted neighborhood density, whereas the reverse was true for the other series. Lexical neighborhood was found to affect word recognition in much the same way as lexical status.

Humans↗

Development and phonetic differentiation of speech movement patterns.

It is often hypothesized that speech production units are less distinctive in young children and that generalized movement primitives, or templates, serve as a base on which distinctive, mature templates are later elaborated. This hypothesis was examined by analyzing the shape and stability of single close-open speech movements of the lower lip recorded in 4-year-old, 7-year-old, and adult speakers during production of utterances that varied in only a single phoneme. To assess the presence of a generalized template, lower lip movement sequences were time and amplitude normalized, and a pattern recognition procedure was implemented. The findings indicate that speech movements of children already converged on phonetically distinctive patterns by 4 years of age. In contrast, an index of spatiotemporal stability demonstrated that the stability of underlying patterning of the movement sequence improves with maturation.

Adult↗

Articulatory rate and perceptual constancy in phonetic perception.

The perception of syllable-initial stop consonants as voiced (/b/, /d/, /g/) or voiceless (/p/, /t/, /k/) was shown to depend on the prevailing rate of articulation. Reducing the articulatory rate of a precursor phrase causes a greater proportion of test consonants to be identified as voiced. Subsequent experiments demonstrated that this effect depends almost entirely on variation in the duration of the syllable immediately preceding the test syllable; this, the duration of the intervening silent stop closure, and the duration of the test syllable itself all influenced the identification of the stop as voiced or voiceless. Variation in the tempo of a nonspeech melody produced no effect on the perception of embedded test syllables. Those manipulations which produce the major part of the influence of rate do so not by changing the context in which the stop is perceived, but rather by changing temporal concomitants of the constriction, occlusion, and release phases of the articulation of the stop itself. For this reason, an explanation for such effects based on extrinsic timing in perception is found to be wanting. Timing should, in the main, be regarded as intrinsic to the acoustical specifications of phonetic events, a view that is compatible with recent reformulations of the problem of timing control in speech production.

Adolescent↗

Phonetic inventory development in young cochlear implant users 6 years postoperation.

Increases in the phonetic inventories of a group of 9 children in the fifth and sixth years of experience with a cochlear implant are reported, extending a previous 4-year study (T. A. Serry & P. J. Blamey, 1999). Thirty-six out of 44 phones in Australian English reached the criterion of 50% correct in the conversational samples of 5 or more children. This level of performance corresponds to intelligible, but not completely natural, speech. The rate of improvement in the sixth year was slow, indicating a probable plateau in performance. The 8 phones that did not attain the 50% criterion in 5 or more children were /see text/. Potential reasons for the slow development or nondevelopment of these phones include very low frequency of occurrence for /see text/ and the perceptual and articulatory characteristics of /see text/. /see text/ is also subject to a high degree of allophonic variation in the fluent speech of normally hearing speakers, probably accounting for much of the variability in its articulation in the conversational samples.

Child↗

In search of the auditory, phonetic, and/or phonological problems in dyslexia: context effects in speech perception.

There is a growing consensus that developmental dyslexia is associated with a phonological-core deficit. One symptom of this phonological deficit is a subtle speech-perception deficit. The auditory basis of this deficit is still hotly debated. If people with dyslexia, however, do not have an auditory deficit and perceive the underlying acoustic dimensions of speech as well as people who read normally, then why do they exhibit a categorical-perception deficit? A potential answer to this conundrum lies in the possibility that people with dyslexia do not adequately handle the context-dependent variation that speech signals typically contain. A mathematical model simulating such a sensitivity deficit mimics the speech-perception deficits attributed to dyslexia. To assess the nature of the dyslexic problem, the authors examined whether children with dyslexia handle context dependencies in speech differently than do normal-reading individuals. Contrary to the initial hypothesis, children with dyslexia did not show less context sensitivity in speech perception than did normal-reading individuals at auditory, phonetic, and phonological levels of processing, nor did they reveal any categorization deficit. Instead, intrinsic properties of online phonological processes, not phonological representations per se, may be impaired in dyslexia.

Acoustic Stimulation↗

Effects of auditory feedback and phonetic context on stomal noise in laryngectomized speakers.

Stomal noise intensity during esophageal speech was measured in 7 laryngectomized subjects during amplified monaural auditory feedback and during control conditions without feedback. A significant (5-10 dB) reduction in stomal noise was observed when auditory feedback was applied. The conditions without feedback were designed to provide additional information regarding the effects of the initial phonetic element in the esophageal speech token on stomal noise. During the control conditions, esophageal speech tokens beginning with voiceless consonants resulted in significantly more stomal noise than was present for the other speech tokens. Clinical implications of the findings are discussed.

Aged↗

Phonetic inventories of 2- and 3-year-old children.

This report provides quasi-longitudinal independent analysis data on two groups of 10 children at 2:0 (years:months), 2:5, 2:9, and 3:3. The analysis included word-initial and word-final phonetic inventories of consonant singletons and clusters and a summary of the relative frequency of seven word shapes. The results indicated that these children were gradually "filling in the gaps" with sounds previously reported to be lacking in slightly younger children.

Age Factors↗

The interactions of amplitude and phonetic quality in esophageal speech.

Levels of isolated vowels and the influence of consonant environment on vowel level were determined for three esophageal speakers and three normal speakers. Twenty lists of isolated vowels and diphthongs and 576 monosyllabic words were used as the stimuli. The results revealed that esophageal speakers had an 11-dB reduction in SPL compared to normal speakers. The greatest level was observed on the vowels /i/ and /u/. Differences between normal and esophageal speakers are discussed in terms of absolute level and phonetic environment.

Aged↗

Disambiguation of ditropic sentences: acoustic and phonetic cues.

In a previous study, we demonstrated that listeners were highly successful in identifying the intended meaning of spoken ditropic sentences (those which may carry either a literal or an idiomatic meaning) when speakers were instructed to convey the distinction. The present communication reports on acoustic and phonetic analyses carried out with the goal of identifying cues that distinguished the literal and idiomatic utterances. Certain prosodic differences were observed. Literal utterances were systematically longer than idioms. This was partly due to increased use of pauses, as well as to increased duration of major lexical items. Moreover, literal sentences were typically characterized by greater numbers of pitch contours (discernible rise-fall excursions of fundamental frequency) and open junctures than were idiomatic utterances. In addition to suprasegmental contrasts, articulatory distinctions--corresponding to lento-allegro phonological rules--were also observed. These distinctions directly reflect the structural differences intrinsic to the two types of utterances. A literal sentence is formulated by the organization of constituent words and phrases. Idioms, on the other hand, are holistic units, largely nontransparent to syntactic structure or the usual meaning of the lexical members.

Humans↗

An instrumental phonetic study of lingual activity in articulation-disordered children.

Traditional auditory-based assessment procedures for diagnosing articulation disorders are limited in that they provide no direct information on activities of the speech organs. In this study electropalatography (EPG) was used to obtain details of tongue contacts with the hard palate in 4 articulation-disordered children, 2 of whom had been categorized as dysarthric. Their lingual-palatal contact patterns during four repetitions of word lists containing lingual consonants in different phonetic environments, were compared with each other and with a group of normal speakers. EPG provided relevant diagnostic information in that all 4 experimental subjects showed patterns that differed from the normals in both spatial configuration and variability. The nature of their distorted patterns allowed a tentative diagnosis of 2 of the children as verbal dyspraxic.

Alveolar Process↗

Some constraints on functionally disordered phonologies: phonetic inventories and phonotactics.

The phonological systems of 40 functional misarticulators, ages 40 to 80 months were examined in terms of the nature and variation of phonetic inventories and phonotactic constraints. It was found that these properties of disordered systems were governed by severe constraints that yielded a typological characterization of such systems along with associated implicational laws. The principles governing disordered systems were also found to parallel closely the principles governing normal first language acquisition. The evidence suggests that at least these properties of disordered systems represent delays in the normal acquisition process and are not otherwise deviant. The assessment and treatment of functional disorders along with the projection of learning patterns can thus appeal to principles governing such phonological systems.

Articulation Disorders↗