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[Phonetic results after surgery of laryngotracheal stenoses in children].

The quality of the results of laryngotracheoplasties is clear evidence of the progress made in the treatment of stenoses involving the larynx and the trachea in children. the surgeon is no longer limited to helping the child breath correctly via the natural airways but can also concentrate on phonatrics since dysphonia is frequent after laryngotracheoplasty. Vocal production of 23 children who had undergone surgery for laryngotracheal stenosis was evaluated subjectively by a panel of listeners and objectively on the basis of the pitch and intensity of the voice, rate of speech and maximal time of phonation. In 11 children over the age of 5 years, assisted assessment of the voice completed the study. In 69.5% of the cases, the voice was subjectively considered to be satisfactory. Voice was considered clear in 52% of the cases. Speech flow was impaired in 39% due to frequent breath taking. Objective parameters revealed that pitch was slightly impaired (256 Hz) with a tendancy to normalize near puberty. The intensity of the voice (77 dB) and mean maximum phonation time (7 s) decreased. The phonotary quotient (270 ml/sec), jitter (1.4%) and leakage of the glottis (2.02 cm3/dB/s) were slightly above the normal range. The spectra of the voices were richly furnished with harmonics up to about 1 000 Hz above which air noises increased. An attempt was made to correlate the analysis of the voice with the characteristics of the stenosis and with the therapeutic methods used. The results would suggest the iatrogenic nature of prolonged canulation and of increasing the size the size of the posterior cricoid.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

Proper function, phonetics, and aesthetics achieved with implant-supported restorations: a multidisciplinary approach.

In a multidisciplinary restoration of the edentulous patient, close cooperation of involved personnel is essential during the treatment planning and the restorative procedures. This presentation is an overview of the rehabilitation of the edentulous maxilla, posterior maxilla, and the challenges of the single tooth implant-supported restorations. The prerequisite of teamwork is emphasized, past achievements and benefits of this treatment modality are reviewed, and three prosthetic challenges addressed. Clinical cases are used to illustrate the presentation.

Dental Implantation, Endosseous↗

Morphologic comparison of two neutral zone impression techniques: a pilot study.

STATEMENT OF PROBLEM: Several studies have compared dentures fabricated using neutral zone and conventional techniques. However, studies comparing swallowing and phonetic techniques for assessing the location and shape of the neutral zone could not be identified in the literature. PURPOSE: The purpose of this pilot study was to compare the outline form of the phonetic and swallowing neutral zone impression techniques for the same subjects. MATERIAL AND METHODS: Nine denture wearers with advanced mandibular ridge resorption were included in this study. For each subject 2 trays were prepared in autopolymerizing acrylic resin. One method used phonetics and tissue conditioner to shape the neutral zone; the second method used swallowing and modeling plastic impression compound. The resulting neutral zone impressions were leveled to the same occlusal height by gently grinding the occlusal surface on sandpaper until it corresponded with landmarks (corners of the mouth, two thirds of the height of the retromolar pads, bilaterally) noted on the cast. The impression was inverted onto graph paper, and the contour was outlined with a lead pencil. One impression was made for each subject, for each technique. The buccal contours of both neutral zones coincided at the median line. The maximum distance between the zones was measured in a buccolingual direction in the anterior, premolar, and molar regions bilaterally. When the location of the phonetic neutral zone in relation compared to the swallowing neutral zone was buccally oriented, a plus score was given. When the phonetic neutral zone was lingually located, a minus score was given. When the 2 lines coincided, a score of 0 was given. Measurements were made from direct readings on the graph paper. Statistical analysis was performed using the Sign test (alpha=.05). RESULTS: Significant differences were noted buccally in the left molar (P =.031) and right molar (P =.003) regions and also in the left and right premolar regions (P =.007), where the swallowing neutral zone was found to be located buccal to the phonetic neutral zone. Significant differences were also noted lingually, in the right premolar region (P =.015), where the swallowing neutral zone was found to be located lingual to the phonetic neutral zone. There was no significant difference between the techniques for the anterior region. CONCLUSION: Within the limits of this study, the phonetic neutral zone appears to be narrower posteriorly compared to the swallowing neutral zone, thus limiting premolar and molar positioning.

Aged↗

The temporal signatures of semantic and phonological activations for Chinese sublexical processing: an event-related potential study.

A large number of Chinese characters are made up by pairing a semantic radical and a phonetic radical. The phonetic radical usually gives a phonological clue for the pronunciation of the whole character but does not contribute to its meaning. Using an event-related potential (ERP) measurement, the present study was able to trace the very intricate interplay between phonological and semantic information embedded in the phonetic radical. It was found that, within the first 50 to 100 ms of perceiving the character, the semantic information of the phonetic radical was better preserved when the constituent phonetic radical provided a valid phonological clue (e.g., regular phonogram) than when it contained an invalid phonetic cue (e.g., irregular phonogram). However, no trace of semantic information from the phonetic radical was preserved after 300 ms. These ERP results detail the neuropsychological steps in reading Chinese and support the framework of the lexical constituent model.

Adult↗

When theories of speech meet the real world.

Two theories of speech--one quite conventional, the other much less so--account very differently for the biological advantage of speech over writing/reading. The guiding assumption of the more conventional theory is that the elements of speech are sounds, and that these are served by processes of motor control and auditory perception that are in no way specialized for language. Accordingly, there must be a cognitive stage, beyond action and perception, where the motor and auditory representations are somehow invested with linguistic significance. On the conventional view, then, the sounds of speech are just like the letters of the alphabet. Neither has more than an arbitrary relation to language, hence the difference between them is trivially a matter of which of the equally large gaps between signal and message needs to be bridged. On the less conventional theory, the ultimate constituents of speech are not sounds, but articulatory gestures. Having evolved exclusively in the service of language, they form a natural class, a phonetic modality. Being phonetic to begin with, they do not require to be made so by cognitive translation. And that, very simply, is the advantage of speech over writing/reading. Speech has the corollary advantage that it is managed by a module biologically adapted to circumvent limitations of tongue and ear by automatically coarticulating the constituent gestures and coping with the complex acoustic consequences. But a result is that awareness of phonetic structure is not normally a product of having learned to speak: The module "spells"--that is, sequences phonetic segments--for the speaker and recovers the segments for the listener, leaving both in the dark about the way that is done; the gestural representations are immediately phonetic in nature, precluding the cognitive translation that would bring them to notice; and coarticulation destroys all correspondence in segmentation between acoustic and phonetic structures, making it that much harder to demonstrate the alphabetic nature of speech at the acoustic surface. Accordingly, special difficulty in becoming literate might be caused by a weakness of the phonetic module, for that would produce primary representations of a fragile sort, with the consequence that they would be that much harder to bring to awareness--as is required if they are to serve writers and readers as the units of an alphabetic script--and also that much less able to bear the weight of working memory.

Awareness↗

Speech perception by infants: categorization based on nasal consonant place of articulation.

This study examined the ability of six-month-old infants to recognize the perceptual similarity of syllables sharing a phonetic segment when variations were introduced in phonetic environment and talker. Infants in a "phonetic" group were visually reinforced for head turns when a change occurred from a background category of labial nasals to a comparison category of alveolar nasals . The infants were initially trained on a [ma]-[na] contrast produced by a male talker. Novel tokens differing in vowel environment and talker were introduced over several stages of increasing complexity. In the most complex stage infants were required to make a head turn when a change occurred from [ma,mi,mu] to [na,ni,nu], with the tokens in each category produced by both male and female talkers. A " nonphonetic " control group was tested using the same pool of stimuli as the phonetic condition. The only difference was that the stimuli in the background and comparison categories were chosen in such a way that the sounds could not be organized by acoustic or phonetic characteristics. Infants in the phonetic group transferred training to novel tokens produced by different talkers and in different vowel contexts. However, infants in the nonphonetic control group had difficulty learning the phonetically unrelated tokens that were introduced as the experiment progressed. These findings suggest that infants recognize the similarity of nasal consonants sharing place of articulation independent of variation in talker and vowel context.

Child Language↗

Comparison of alaryngeal voice and speech.

The aim of the research was to compare voice and speech in three groups of alaryngeal speakers: 1) patients using esophageal speech, 2) patients with electro-acoustical speech aids and 3) patients with voice prostheses. Acoustic analysis and pronunciation tests were used for the analysis. Acoustic analysis included fundamental frequency, maximum phonation time, jitter, shimmer and intensity. Pronunciation parameters were: phonetic block duration, number of syllables in a phonetic block, rate of speech, maximum number of syllables in a phonetic block and rate of articulation in a maximal phonetic block. Our results demonstrated the advantages of tracheoesophageal puncture with implantation of a voice prosthesis over the other two techniques of alaryngeal speech. Voice and pronunciation with voice prostheses were closer to normal in many parameters: fundamental frequency, maximum phonation time, jitter, shimmer, duration of a phonetic block, number of syllables in a phonetic block, rate of speech and rate of articulation in maximal phonetic block.

Acoustics↗

Behavioral examinations of the level of auditory processing of speech context effects.

One of the central findings of speech perception is that identical acoustic signals can be perceived as different speech sounds depending on adjacent speech context. Although these phonetic context effects are ubiquitous in speech perception, their neural mechanisms remain largely unknown. The present work presents a review of recent data suggesting that spectral content of speech mediates phonetic context effects and argues that these effects are likely to be governed by general auditory processes. A descriptive framework known as spectral contrast is presented as a means of interpreting these findings. Finally, and most centrally, four behavioral experiments that begin to delineate the level of the auditory system at which interactions among stimulus components occur are described. Two of these experiments investigate the influence of diotic versus dichotic presentation upon two phonetic context effects. Results indicate that context effects remain even when context is presented to the ear contralateral to that of the target syllable. The other two experiments examine the time course of phonetic context effects by manipulating the silent interval between context and target syllables. These studies reveal that phonetic context effects persist for hundreds of milliseconds. Results are interpreted in terms of auditory mechanism with particular attention to the putative link between auditory enhancement and phonetic context effects.

Acoustic Stimulation↗

Form-based priming in spoken word recognition: the roles of competition and bias.

Phonological priming of spoken words refers to improved recognition of targets preceded by primes that share at least one of their constituent phonemes (e.g., BULL-BEER). Phonetic priming refers to reduced recognition of targets preceded by primes that share no phonemes with targets but are phonetically similar to targets (e.g., BULL-VEER). Five experiments were conducted to investigate the role of bias in phonological priming. Performance was compared across conditions of phonological and phonetic priming under a variety of procedural manipulations. Ss in phonological priming conditions systematically modified their responses on unrelated priming trials in perceptual identification, and they were slower and more errorful on unrelated trials in lexical decision than were Ss in phonetic priming conditions. Phonetic and phonological priming effects display different time courses and also different interactions with changes in proportion of related priming trials. Phonological priming involves bias; phonetic priming appears to reflect basic properties of activation and competition in spoken word recognition.

Adult↗

Closest speaking space during the production of sibilant sounds and its value in establishing the vertical dimension of occlusion.

The purpose of this investigation was to determine whether the production of sibilant sounds involved adopting a jaw position that corresponded to the closest vertical speaking space (CSS), by analysis of the smallest vertical excursion of the mandible during the performance of different phonetic exercises. A further objective was to establish the variability in the CSS produced by individual sibilant phonemes. Thirty young adult subjects had their CSS determined during three separate phonetic tests, using a kinesiograph (Sirognathograph, Siemens A.G., Benshiem, Germany) and a Bio-Pak (BioResearch Associates Inc., Milwaukee, WI) jaw-tracking software program. The first test was a general phonetic articulation test containing all the sounds of the English language and specifically including all six sibilant word sounds. The second phonetic test contained the six sibilant sound making up a short sentence. The third test included six single words, each expressing a different sibilant sound. No statistically significant difference among the mean CSS determined in each of three exercises was demonstrable. A phonetic test containing all sibilant sounds produced a CSS equivalent to that of a test containing all speech sounds. The vertical component of the CSS was also independent of the form or duration of the phonetic tests containing the sibilant word sounds used in this investigation. The CSS determined for 5 of the individual sibilant phonemes in the third exercise differed (p < 0.05) from that calculated for the three complete exercises. It was concluded that voicing sibilant phonemes, or word sounds, does cause the subject to adopt the CSS.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Characterizing the influence of native language experience on adult speech perception.

Previous cross-language research has indicated that some speech contrasts present greater perceptual difficulty for adult non-native listeners than others do. It has been hypothesized that phonemic, phonetic, and acoustic factors contribute to this variability. Two experiments were conducted to evaluate systematically the role of phonemic status and phonetic familiarity in the perception of non-native speech contrasts and to test predictions derived from a model proposed by Best, McRoberts, and Sithole (1988). Experiment 1 showed that perception of an unfamiliar phonetic contrast was not less difficult for subjects who had experience with an analogous phonemic distinction in their native language than for subjects without such analogous experience. These results suggest that substantive phonetic experience influences the perception of non-native contrasts, and thus should contribute to a conceptualization of native language-processing skills. In Experiment 2, English listeners' perception of two related nonphonemic place contrasts was not consistently different as had been expected on the basis of phonetic familiarity. A clear order effect in the perceptual data suggests that interactions between different perceptual assimilation patterns or acoustic properties of the two contrasts, or interactions involving both of these factors, underlie the perception of the two contrasts in this experiment. It was concluded that both phonetic familiarity and acoustic factors are potentially important to the explanation of variability in perception of nonphonemic contrasts. The explanation of how linguistic experience shapes speech perception will require characterizing the relative contribution of these factors, as well as other factors, including individual differences and variables that influence a listener's orientation to speech stimuli.

Adolescent↗

Linguistic processing in idiopathic generalized epilepsy: an auditory event-related potential study.

PURPOSE: Auditory processing of increasing acoustic and linguistic complexity was assessed in children with idiopathic generalized epilepsy (IGE) by using auditory event-related potentials (AERPs) as well as reaction time and performance accuracy. METHODS: Twenty-four children with IGE [12 with generalized tonic-clonic seizures (GTCSs), and 12 with absence seizures (ASs)] with average intelligence and age-appropriate scholastic skills, uniformly medicated with valproic acid (VPA), and 20 healthy controls, performed oddball discrimination tasks that consisted of the following stimuli: (a) pure tones; (b) nonmeaningful monosyllables that differed by their phonetic features (i.e., phonetic stimuli); and (c) meaningful monosyllabic words from two semantic categories (i.e., semantic stimuli). RESULTS: AERPs elicited by nonlinguistic stimuli were similar in healthy and epilepsy children, whereas those elicited by linguistic stimuli (i.e., phonetic and semantic) differed significantly in latency, amplitude, and scalp distribution. In children with GTCSs, phonetic and semantic processing were characterized by slower processing time, manifested by prolonged N2 and P3 latencies during phonetic processing, and prolongation of all AERPs latencies during semantic processing. In children with ASs, phonetic and semantic processing were characterized by increased allocation of attentional resources, manifested by enhanced N2 amplitudes. Semantic processing also was characterized by prolonged P3 latency. In both patient groups, processing of linguistic stimuli resulted in different patterns of brain-activity lateralization compared with that in healthy controls. Reaction time and performance accuracy did not differ among the study groups. CONCLUSIONS: AERPs exposed linguistic-processing deficits related to seizure type in children with IGE. Neurologic follow-up should therefore include evaluation of linguistic functions, and remedial intervention should be provided, accordingly.

Acoustic Stimulation↗

Are your minimal pairs too neat? The dangers of phonemicisation in phonology therapy.

Using Conversation Analysis (CA) to look at the interactional dynamics of therapy repair sequences, this paper shows exactly what happens for children when idealised misrepresentations of their phonology are used in therapy. The primary video extract involves a 4-year-old phonologically disordered boy and his therapist. It is not new to warn of the dangers of overlooking any subtle phonetic distinctions that the phonologically disordered child may have but this paper adds something new to the debate. The child's interpretation of the adult's prior turn in the sequence is made explicit and the likelihood of the child producing phonetic revision following an error is seen to be affected by the way the therapist chooses to initiate repair. This is especially true where a 'redoing' of the error is incorporated into such an initiation, when the child's phonetic output is 'tidied up' so that it fits in with the neat minimal pair which forms part of the therapy programme. This is one factor that can be seen to militate against appropriate phonetic repair by the child, especially when used in certain turn structures that are routinely associated with lexical rather than phonetic matters. When the adult 'redoing' more accurately reflects the child's output phonetic revision is more likely to occur. Implications for assessment and therapy are drawn from this evidence, with accurate phonological assessment and continuing interactional error analysis being recommended.

Child, Preschool↗

Phonological and semantic processes influence beginning readers' ability to learn to read words.

Children (4 to 6 years of age) were taught to associate printed 3- or 4-letter abbreviations, or cues, with spoken words (e.g., bfr for beaver). All but 1 of the letters in the cue corresponded to phonemes in the spoken target word. Two types of cues were constructed: phonetic cues, in which the medial letter was phonetically similar to the target word, and control cues, in which the central phoneme was phonetically dissimilar. In Experiment 1, children learned the phonetic cues better than the control cues, and learning correlated with measures of phonological skill and knowledge of the meanings of the words taught. In Experiment 2, the target words differed on a semantic variable-imageability-and learning was influenced by both the phonetic properties of the cue and the imageability of the words used.

Analysis of Variance↗

Event-related brain potentials elicited by rhyming and non-rhyming pictures differentiate subgroups of reading disabled adolescents.

Event-related brain potentials were recorded while disabled adolescent subjects read and judged whether two sequentially presented pictures had names that rhymed. Subjects with relatively good phonetic skills displayed an N400 priming effect, i.e., a significant reduction in the amplitude of the negative peak, occurring approximately 400 msec post-stimulus, for pictures with names that rhymed with preceding pictures as compared with pictures that had names that did not rhyme with the prime. No such effect was evident for subjects with relatively poor phonetic skills. This lack of an N400 priming effect provides evidence for a reduction in neural capacity and/or activation during phonological processing in the subjects with poor phonological skills. Demonstrating the N400 priming effect to be stronger in one group of reading disabled subjects, compared to another, supports the position that specific subtypes of reading disability exist. In addition to the stronger N400 priming effect, the phonetically stronger group also exhibited an enhanced negativity, from 700 to 1,000 msec after target stimulus onset, compared to phonetically inferior subjects. This finding replicates earlier work and possibly reflects a higher level of confidence in the group with better phonetic skills.

Adolescent↗

Flexible coding in word recognition.

An experiment was designed to examine the contribution of phonetic information in the processing of words in tachistoscopic recognition masking. Following stimulus presentation, subjects were required to indicate which of two alternatives had appeared. On trials containing word stimuli, the alternatives were either phonetically identical (SENT, CENT) or not (SOLD, COLD). Recognition performance was inferior in the former case, provided conditions were not structured to discourage reliance on phonetic information. The findings were interpreted as showing that more than one type of coding process can underly the word superiority effect. Phonetic information is ordinarily used to code words in this type of task, but an alternative processing tactic (e.g., one relying on visual or perhaps semantic codes) can also be effectively used in word recognition when phonetic information does not discriminate well among response alternatives.

Discrimination, Psychological↗

Orthography and familiarity effects in word processing.

Both orthographic regularity and visual familiarity have been implicated as contributors to the efficiency of processing visually presented words. Our studies sought to determine which of the internal codes representing words in the nervous system are facilitated by these two variables. To do this, sets of letter strings in which orthography and familiarity were factorially combined were used as the basis for physical, phonetic, semantic, and lexical judgments. The data indicated consistent effects of orthography on the activation of all codes. These effects were seen in same-different matching and in judgments of stimulus orientation, which are based on visual codes; in judgments of pronounceability based on phonetic codes; in judgments of meaningfulness based on semantic codes; and in lexical decisions, which are based on phonetic and semantic codes together. Familiarity, on the other hand, had a clear influence on the activation of semantic codes and to a lesser extent affected phonetic codes. Despite previous positive results found in matching letter strings, however, no influence of familiarity occurred in judgments based on visual codes once evidence for criterion shifting was eliminated. Our negative results included direct tests of facilitation in matching acronyms (e.g., FBI) and in matching both regular and irregular strings familiarized by specific training. It now appears that earlier findings of visual familiarity effects may be attributed to response biases resulting from the activation of higher level codes sensitive to familiarity, and to the use of small sets of training stimuli that allowed subjects to induce orthographic-like rules. The results obtained so far with our methods seem to reconcile an inconsistent literature by showing that speeded decisions based on visual codes are most strongly influenced by rule-governed processing mechanisms sensitive to orthographic structure, whereas decisions based on phonetic and semantic codes are affected about equally by rule-governed mechanisms and by stimulus-specific mechanisms sensitive to familiarity. This conclusion may lead to changes in notions of how effective various kinds of visual training are likely to be at different stages in the acquisition of reading skill.

Discrimination Learning↗

Discrimination of non-native consonant contrasts varying in perceptual assimilation to the listener's native phonological system.

Classic non-native speech perception findings suggested that adults have difficulty discriminating segmental distinctions that are not employed contrastively in their own language. However, recent reports indicate a gradient of performance across non-native contrasts, ranging from near-chance to near-ceiling. Current theoretical models argue that such variations reflect systematic effects of experience with phonetic properties of native speech. The present research addressed predictions from Best's perceptual assimilation model (PAM), which incorporates both contrastive phonological and noncontrastive phonetic influences from the native language in its predictions about discrimination levels for diverse types of non-native contrasts. We evaluated the PAM hypotheses that discrimination of a non-native contrast should be near-ceiling if perceived as phonologically equivalent to a native contrast, lower though still quite good if perceived as a phonetic distinction between good versus poor exemplars of a single native consonant, and much lower if both non-native segments are phonetically equivalent in goodness of fit to a single native consonant. Two experiments assessed native English speakers' perception of Zulu and Tigrinya contrasts expected to fit those criteria. Findings supported the PAM predictions, and provided evidence for some perceptual differentiation of phonological, phonetic, and nonlinguistic information in perception of non-native speech. Theoretical implications for non-native speech perception are discussed, and suggestions are made for further research.

Adolescent↗