Tongue Contact Research Articles

舌・口底切除患者に対する舌接触補助床装置前後の言語所見

われわれは12名の舌・口底切除患者の構音障害に対し, 舌接触補助床 (以下, 補助床) を応用し, その効果を語音発語明瞭度 (以下, 語明度) の検査結果から検討した。日本語100音の語明度は補助床装着前52.2±14.5%, 装着後64.4±10.4%で, 舌音79音語明度は補助床装着前42.3±17.4%, 装着後57.1±12.7%であった。また構音様式・構音点別では両唇破裂音, 両唇鼻音, 歯茎破裂音, 歯茎通鼻音, 弾き音, 硬口蓋破擦音および母音において, 舌接触部位別では舌尖音, 舌尖・舌背音および舌背音でそれぞれ補助床装着後に有意な改善が認められた。

Coarticulation effects in American English velar and alveolar stop consonants: An electropalatographical and acoustical analysis

Coarticulation effects of post-consonantal vowels on the place of tongue contact for American English velar and alveolar stop consonants were examined through simultaneous measurements with a new type of electropalatography (EPG) and with spectral analysis. The EPG system, developed by the author, has 49 electrodes, and is used to observe lingual contact with the soft palate, hard palate, and upper incisal teeth. It can record the palatograms at a 7.8-ms frame interval. The resulting palatograms can be compared with acoustic spectra made from simultaneous speech recordings. One American male subject produced VCV utternances in which the consonants were /k/, /g/, /t/, and /d/, and the vowels were /a/, /o/, /u/, /e/, and /i/. The results confirm that the tongue contact position for American English velar stop consonants is more strongly influenced by the vowels following it than for alveolar stop consonants. The value of F2 around the release burst was consistent with the strong coarticulation effects observed with the EPG.

Effects of intraoral prosthetics on swallowing in patients with oral cancer.

The swallowing patterns of four patients with oral cancer with intraoral palate reshaping/lowering protheses were studied with and without their prostheses 3 months postoperatively. The prostheses resulted in improved swallow efficiency, increased duration of tongue contact to the pharyngeal wall, and improved speed of movement of the bolus from the valleculae to the pyriform sinus. These results emphasize the effects of the tongue on the pharyngeal as well as oral stage of the swallow.

Effect of sensory input from the tongue on jaw movement in normal feeding in the opossum.

Opossums were presented with solid and liquid foods. The movements of the jaw and tongue were recorded cineradiographically together with recordings of the EMG activity in muscles opening the jaw and moving the base of the tongue (hyoid). The jaw opening in each cycle was in two stages--01 and 02; 01 had a constant amplitude irrespective of the food ingested. Ingestion of liquid (which involved continuous accumulation of a liquid bolus in the valleculae prior to swallowing) was associated with cycles of oral movement in which 02 was small; tongue retraction was associated with this opening. In contrast, solid and semisolid food ingestion was associated with large angles of jaw opening in 02 that also coincided with the tongue retraction. In this latter case a characteristic pattern of EMG activity, in which all the muscles moving the hyoid were simultaneously active, was added to the pattern seen in lapping; this additional activity had an EMG pattern that was consistent with a jaw opening reflex. The findings contrast with other reports that the jaw opening reflex is suppressed in mastication. Experimentally induced tongue contact with a variety of solid surfaces during lapping (an activity involving accumulation of a liquid bolus in the valleculae) induced neither increased jaw opening nor the additional EMG pattern. However, in situations when there was no bolus in the valleculae, additional jaw opening activity was elicited when the tongue contracted solids intra- or extra-orally. It is suggested that the ability of sensory input, from the anterior tongue, to elicit a jaw opening reflex and to change the type of jaw/tongue cycle was dependent upon the extent of bolus accumulation in the valleculae and therefore indirectly upon the consistency of the food.

The use of instrumental phonetics in the assessment and remediation of three cleft palate children with late repair of the hard palate

Cleft palate children with relatively late repairs of the hard palate often manifest abnormal speech patterns which can severely disrupt intelligibility. However, the precise nature of these abnormal patients is often difficult to determine by impressionistic judgments, and their problems are frequently ongoing and resistant to conventional therapy. In this study we investigated the speech of three such children whose anterior fistulas were successfully closed at 7,5.5 and 5 years respectively. The instrumental techniques of pneumotachography (for measuring air pressure/flow) and electropalatography (for recording spatial and temporal details of tongue contact on the hard palate) were used to assess the children’s speech. Hearing was normal and resonance was within normal perceptual limits, but the pressure/flow measurements did reveal some slightly abnormal closure patterns of the velopharyngeal port. Electropalatographic (EPG) results confirmed that tongue contacts were frequently abnormal, particularly on those sounds involving anterior placement of the tongue in the alveolar region. EPG patterns showed generally more extensive contact than normal for alveolar stops and retracted contact patterns particularly for fricative CT). Abnormal velar contact was present for bilabial stops in one child. It was hypothesised that alveolar fricatives are most likely to be impaired because they are generally more complex and involve greater precision in muscular control and kinaesthetic feedback. Articulatory problems could be related to possible early hearing loss, the relatively late repair, presence of scar tissue interfering with tactile feedback, and shape of the palate. Therapy using EPG as a visual feedback device was successful in improving articulatory placements in all three children.

Chemical access to the vomeronasal organs of the lizard Chalcides ocellatus

A functional association between tongue flicking and vomeronasal organ chemoreception in lizards has been assumed frequently, but never tested. To test this hypothesis, a cotton swab soaked in prey extract mixed with [3H]proline was touched ten times to the snouts of normal and tongueless lizards (Chalcides ocellatus), as well as normal lizards whose vomeronasal organ (VNO) ducts had been sealed with a tissue adhesive. Additionally, such a swab was held approximately 0.5 cm in front of the snout of normal and tongueless lizards for 1 min, which allowed no contact by tongueless animals and tongue contact only by normal lizards. Using autoradiography, substantial and comparable concentrations of labeled molecules were detected in the mouths, VNO ducts, and VNOs of normal subjects in both conditions, as well as tongueless lizards whose snouts made physical contact with swabs. No label was evident in VNOs of tongueless animals that did not contact swabs or normal animals with sealed VN ducts. Labeling was not apparent generally in the olfactory epithelium. These results suggest that: 1) the tongue is not required for, nor does it increase, chemical delivery to VNOs when snout contact occurs; 2) the tongue transfers molecules from the external environment to the oral region; 3) it is unlikely that nonvolatile chemicals reach the olfactory epithelium via an oral route; and 4) tissue adhesive is an effective means of preventing chemical access to the VN organs.

Measuring coarticulation and variability in tongue contact patterns

Instrumental assessment of pathological speech is of limited use unless normal variability can be quantitatively defined. An attempt was made to quantify the variability of tongue contact patterns at certain stages during the pronunciation of VCV sequences by a normal speaker, in terms of the contact totals registered by an electropalatograph system. Of specific interest were the total contact area during the vowels and the rate of change of contact for consonant closures and releases. The results are discussed in the light of some current theories of coarticulation and their implications for speech assessment.

歯列を含むパラトグラムの画像処理による標準形態

(palatogram). The subjects were 30 dentulous adults (21 men, 9 women). The artificial palates made of black vinyl seat covering the palate and occlusal surfaces of maxillary teeth were coated with white alginate powder and inserted into the mouths of the subjects. After pronunciation of the test sound, the tongue contact areas on artificial palate were demonstrated by wetting of powder and changing in color from white to black. Thus photographs of the palatograms were Measurements have been made on the tongue contact area of the palate and maxillary teeth during pronunciation of /sa, fi, çi, ka, ki, ta, na, ra, ja/ (palatogram). The subjects were 30 dentulous adults (21 men, 9 women). The artificial palates made of black vinyl seat covering the palate and occlusal surfaces of maxillary teeth wer coated with white alginate powder and inserted into the mouths of the subjects. After pronunciation of the test sound, the tongue contact areas on artificial palate were demonstrated by wetting of powder and changing in color from white to black. Thus photographs of the palatograms were taken. An image processor system was employed for averaging each subject's 5 samples of same sound. The averaged outline of each subject's palatograms were converted to the standardized dental arch form and added and stored into frame memory. The 60-90% of subject's common parts were extracted from the added palatograms of same sound and illustrated in different gray levels. The results indicate that the tongue-to-teeth contact area of each sound differ from the others, however, it's range is confined within cervical half of lingual surface of incisors and lingual cusps of molars.

New developments in electropalatography: A state-of-the-art report

Recent developments in Electropalatography (EPG) as a technique for investigating spatio-temporal details of tongue contacts with the hard palate in both normal and pathological speech are reviewed...

A study of the investigatory behavior of the dairy cow

A commission to investigate the possible ingestion by dairy cattle of air-dropped wildlife baits for vaccination against sylvatic rabies provided an excellent opportunity for a detailed study of bovine investigatory behavior. Twelve unarmed baits (half of which were placed in a bag with liver slurry serving as a fox attractant) were placed in each of two pastures. A group of 9 cows was then allowed to graze freely on each of the pastures from approximately 08.00 to 15.00 h for 5 consecutive days. Continuous direct observation revealed that the tendency of the cows to approach the baits varied with the type of bait encountered, and habituated over the 5-day study. However, once an investigation was initiated, the likelihood of contacting the bait and the manner in which the bait was contacted was not readily influenced by prior exposure to the baits. The type of bait being investigated did not influence the likelihood of a cow making contact, but did influence the manner in which the bait was contacted. Flehmen, which only occurred following head contact with a bait, most commonly followed mouth or tongue contact and was less likely to be employed as cows habituated to the objects being investigated.

Coarticulation effects in Japanese velar stop consonants: Observations with dynamic velography

The positioning of the tongue body is strongly influenced by coarticulation effects. The tongue body contact position for /k/ and /g/ varies especially widely, moving in the direction demanded by the surrounding phonemes. Coarticulation effects of post-consonantal vowels on the place of tongue body contact for Japanese velar stop consonants were observed by dynamic velography. The dynamic velography system, developed by the authors is a 36-electrode electropalatographic technique for observing lingual contact with the soft palate. The resulting velograms can be compared with spectrograms made from simultaneous recordings of speech. Three Japanese male subjects produced VCV utterances with stress on the second syllable. The velogram patterns for [aka], [ako], [aga], [ago] were similar, with contact located at the posterior part of the soft palate. Contact for [ake], [aki], [age], [agi] was located more anteriorly. Thus, as suggested by previous findings, the tongue contact position for Japanese /k/ and /g/ is strongly influenced by the vowels following it.

Preference differences for sucrose solutions in young and aged squirrel monkeys

Licking patterns and molarity preferences, elicited by two sets of sucrose solutions (0.0 to 1.75 M and 1.0 to 3.0 M), were measured in six young and six aged squirrel monkeys. Sucrose preference thresholds were determined for each age group using sucrose concentrations from 0.025 to 0.1 M. Age was unrelated to sucrose preference thresholds. Consummatory activity of all monkeys increased monotonically as sucrose concentrations increased from 0.0 to 1.0 M. Aged, but not young, monkeys continued to increase consumption until sucrose concentrations exceeded 1.5 M. All monkeys increased consumption by increasing number of licks, number of licking bursts and total time spent licking. Unlike young monkeys, aged monkeys displayed high within animal variability of tongue contact times, exponentially decreasing rates of licking at high molarities, constant consumption efficiency decrements, and consistent negative correlations between tongue contact and following tongue off times.

テプレノン改良細粒剤の使用性に関する検討

Teprenone fine granule has excellent feeling of tongue contact, but its marked dustability causes a pharmaceutical problem. We obtained a reformed preparation which aimed at improvement in pharmaceutical preparation while retaining its excellent feeling of tongue contact, and evaluated its pharmaceutical property.As a result, the preparation has high granular uniformity and excellent pharmaceutical fitness, though slightly pales before the feeling of tongue contact. When evaluated from an overall viewpoint, the reformed preparation seems to be better than the control drugs.

Tactile speech reception using augmented Tadoma

Results obtained with Tadoma have set a new standard for the tactile communication of speech [Reed et al., J. Acoust. Soc. Am. 77, 247–257 (1985)]. These results, however, are inferior to those obtained in the normal auditory domain: they are roughly comparable to those obtained by normal‐hearing subjects listening to speech in signal‐to‐noise ratios of 0–6 dB. The goal of the current research is to augment Tadoma with supplementary tactile displays to improve the perception of speech segments. Among the supplementary displays investigated were a vibrotactile display of tongue contact with the hard palate and a vibrotactile display of the short‐term speech spectrum. The tongue‐palate‐contact display was effective for improving the discriminability of pairs of consonants difficult to distinguish through Tadoma; however, neither this display nor the multichannel spectral display proved to be effective for augmenting vowel discriminability. A third approach to augmenting Tadoma currently under investigation involves the tactile reception of cued speech. [Work supported by NSF.]

Observations on the release of /t/

Palatographic data were examined for the release of prevocalic /t/ in both aspirated and unaspirated contexts. Thirty-two tongue contact points in the alveolar region were sampled every 2 ms. Although a plosive burst is a sudden acoustical event, the dynamic tongue release gesture is more gradual. The burst is associated with the sudden opening of a narrow central channel between the tongue and palate. The tongue then continues to pull away from contact centrally, with the final contacts remaining laterally even after voicing for the following vowel has commenced. At some point during the release of /t/, the tongue contact pattern passes through a configuration virtually identical to that for the greatest constriction of /s/. This implies that a brief period of frication generated at the point of release may follow the burst. The sequence of acoustical events at the release of aspirated /t/ would be: burst-frication-aspiration. Tongue releases in a unaspirated context (/st__/) were also examined. The palatographic pattern of tongue release was no different for the unaspirated context, although the timing of its initiation was later relative to the beginning of the following vowel. [Work supported by NIDR.]

Vowel context, rate, and loudness effects on linguapalatal contact patterns in Hindi retroflex /t/

Tongue position for retroflex /t/ has been shown to differ across languages in the contexts of /a/ and certain other vowels. Degree of retroflexion has also been shown to be affected by vowel context [Ladefoged and Bhaskararao, J. Phonet. 11, 291–302 (1983) and references therein]. Since previous studies have not determined whether the place or length of constriction differs as a function of vowel context, this study examined changes in the articulation of Hindi retroflex /t/ as a function of vowel context, and also as a function of speaking rate and loudness. A 96‐channel electropalatograph was used to monitor production of retroflex /t/ in the nonsense words /bitíb/, /batáb/, and /butúb/ spoken in carrier phrase by a native speaker of Hindi. The length of constriction (i.e., the number of contacted rows × 2 mm) changed very little (< 1 mm) as a function of the three factors. However, the anterior‐posterior location of the /t/ constriction shifted dramatically as a function of vowel context. The center of constriction was 3.8 mm more posterior in /u/ than in /i/, and 5.8 mm more posterior in /a/ than in /i/. The pattern and area of tongue contact observed for retroflex /t/ and dental /t/ were virtually identical in the /i/ but not in the /a/ or /u/ context. A similar vowel context effect on retroflex /t/ was observed in speech produced at a fast rate, and in loud speech. [Work supported by NIH grant.]

Articulatory asymmetries.

Tongue contact patterns for /s/ and /l/ were investigated using dynamic palatography. Both spatial and temporal asymmetries were commonly found extending into the vocalic transitions for these consonants. Implications for the adequacy of tongue motion data taken in a single midsagittal plane are discussed, as well as for articulatory interpretation of speech signals and speaker recognition applications.

Some phonetic and syntactic constraints on lingual coarticulation during /kl/ sequences

The effects of vowel context, juncture and rate of utterance on anticipatory co-articulation in /kl/ sequences were studied with the technique of electropalatography, which records details of the location and timing of tongue contacts with the hard palate during speech. Four subjects produced test items in which a variety of different prosodically-marked syntactic junctures fell between the /k/ and /l/, at two different rates of utterance and in two different vowel environments. Co-articulation was measured as the time interval from the release of the /k/ closure to the onset of anterior tongue movement for the /l/. Subjects showed considerable variation in co-articulatory patterns used in most of the test items but there was a clear tendency towards more extensive co-articulation in the fast rate of utterance. Major syntactic boundaries seemed to have little effect on the degree of co-articulation except in the slow rate of utterance, where for three of the four subjects the onset of the anterior movement for /l/ was consistently delayed. Vowel context had little consistent effect in either fast or slow rates.

Asymmetries in placement and timing of alveolar tongue contact patterns for /s/ and /l/

The “central groove” of the tongue for /s/, and the alveolar tongue contact pattern of /l/ frequently show left-right asymmetries. These articulatory asymmetries are highly consistent within an individual, but do not seem to bear a clear relationship to other type of sidedness, such as hand preference. Left-right differences in alveolar and palatal contour have been suggested as a causal factor. The present study employed dynamic palatography with five subjects. Tongue contact for /s/ was initiated earlier on one side, as if to anchor the tongue. Subsequently, a more anterior groove formation followed. Contact and release in a VCV environment were similar, with the side touched first at onset of /s/ being the side to be released later. The side with greater (and usually earlier) contact for /s/ was generally also more widely contacted for /l/, such that the lateral margin of the tongue appeared at times to be free only on one side. Since sidedness was similar for /s/ and /l/, /sl/ blend articulation was simplified. Preliminary results of an experiment in altering the oral contour with a dental appliance, thicker on one side, and the resulting palatographic changes will also be discussed. [Work supported by NIDR.]

Speech adaptation to dental prostheses: The former lisper

Six of 13 former lispers studied reported unusual difficulty in speech adaptation to a dental prosthesis. Palatographic data showed that former lispers tended to make more frequent use of A-P shifts in tongue-palate placement as a compensatory strategy than did normal subjects. Tongue advancement was a common pattern. The nonadaptors showed the highest incidence of A-P tongue contact shifts as a compensatory strategy. Their use of this strategy was the most consistent, and they were more likely to retain the same articulatory speech patterns that were tried initially. Tongue groove width data for sibilants of nonadaptors in the familiar condition showed a substantial incidence of further groove narrowing, a pattern normally seen only when a prosthesis is unfamiliar to the subject. In data on jaw position, nonadapting subjects had either not changed jaw position or adopted a closer jaw position by the end of 2 weeks. In both palatographic and jaw position data, it was possible to distinguish the adapting and nonadapting groups.