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- Articulatory oral space measures using the modified A-SpacePublication . Jesus, Luís M. T.; Araújo, André; Costa, Isabel. M.The X-ray microbeam method for measurement of articulatory dynamics has been used to acquire large amounts of data, with reduced X-ray dosage, resulting in one of the most widely used freely available speech production databases. The X-ray Microbeam Speech Production Database (XRMB-SPD), developed at Wisconsin University, USA, includes a vast amount of coordinate data describing articulatory movements, and acoustic and electroglotographic data collected simultaneously. Honda et al. examined the geometry of the vocal track of American English and Japanese speakers from the XRMB-SPD, using a quadrilateral (A-Space) limited by the palate plane, the anterior nasal spine-menton line, the outline of the posterior pharyngeal wall, and a line parallel to the palatal plane, passing through the menton and extending to the pharyngeal wall. In this study the A-Space of different speakers varied in shape. The vowel articulations adapted to the form of the A-Space whilst consonant articulations were independent. each of the 57 speakers. This was used to measure the articulatory oral space (AOS) in the absence of cephalometric analysis, based on the Modified A-Space described in Fig. 1. Axis Reference electrodes Mobile electrodes Static articulatory coordinates Static mandible coordinates Axis Reference electrodes Mobile electrodes Static articulatory coordinates Static mandible coordinates Axis Reference electrodes Mobile electrodes Static articulatory coordinates Static mandible coordinates MaxOP MaxOP Maxillary occlusal plane Maxillary occlusal plane PHA PHA CON CON COR COR M5 M5 M1 M1 M4 M4 MANm MANm GON GON yy yy MAXn MAXn MAXg MAXg PAL PAL MAXi MAXi MNI MNI MANi MANi GNA GNA UL UL LL LL Mid-sagital plane Mid-sagital plane xx xx M3 M2 The Modified A-Space method was used to select 4 speakers in a study that relates occlusal classes with vowel, fricative and stop production adaptations. It allows the detailed characterization of the XRMB-SPD speakers not just in terms of mid-sagittal-plane area, but also in terms of antero-posterior distance, occlusal plane area, posterior pharynx wall tilt, mandible arch width, and oral cavity volume. This last measure has proven to be far more reliable and has revealed more speaker dependent characteristics than the measure previously proposed in.
- Vowel production in two occlusal classesPublication . Araújo, André; Jesus, Luís M. T.; Costa, Isabel M.; Guerreiro Martins Araújo, Pedro AndréThe influence of occlusal class in speech production has been studied using the X-ray Microbeam Speech Production Database (XRMB-SPD). The objective of the study was to relate the occlusal classes I and II with vowel production adaptations. The “Modified A-Space” method was used to select 4 speakers (1 class I male, 1 class I female, 1 class II male and 1 class II female). Articulatory and acoustic features of the vowels [i, {, A, u] were studied using different tasks and methods. Results show some structural differences related with occlusal class and variance in class II subjects’ structures and articulatory adaptations. The major differences found in the vowels’ formants were between male and female groups. Occlusal class also seems to influence acoustical features of vowels produced by female speakers. Structural differences were found, but subjects showed a high adaptation capacity, being able to adjust their articulators to produce all vowels.
- O uso da X-Ray Microbeam Speech Production Database no estudo da influência da oclusão dentária na produção de sons de falaPublication . Araújo, André; Jesus, Luís M. T.; Costa, Isabel M.A fala é uma actividade neuromotora complexa, usada na comunicação humana cujo entendimento continua a despertar interesse. Actualmente, a investigação tende a unir ciências linguísticas e médicas com novas tecnologias. A terapêutica da fala, responsável pela avaliação e tratamento das perturbações da comunicação humana, tem dado contributos para a evolução do conhecimento da fala numa perspectiva funcional. A XRMBSPD é uma base de dados que usa a técnica imagiológica X-ray Microbeam, e permite simultaneamente uma análise acústica, electroglotográfica e articulatória dinâmica, através da localização em tempo real de eléctrodos colocados em vários pontos da face e do sistema articulatório (língua, lábios e dentes). Usou-se a XRMB-SPD para descrever diferenças acústicas e articulatórias em indivíduos com classes de oclusão dentária diferentes.
- The influence of occlusal class in the production of voiceless fricativesPublication . Araújo, André; Vilarinho, Helena; Jesus, Luís M. T.The aim of this study was to relate the production of voiceless fricatives with the type of dental occlusion. The articulatory gestures during the production of consonant sounds such as the voiceless fricatives /f/, /s/ and /ʃ/, seem to be disturbed for type II class (Angle’s classification) individuals, which frequently require the training of compensatory articulation to get a “normal” acoustic output. This work is central to the first two authors’ clinical practice in Speech and Language Therapy in which it is frequent the need to treat articulatory disorders.
- Clinical analysis in speech and language therapy: Occlusal class and speech productionPublication . Araújo, André; Jesus, Luis M. T.; Costa, Isabel M.Occlusal class refers to the manner that the upper (maxilla) and lower (mandible) dental arches relate. This relation was first described by Angle, who proposed a malocclusion classification based on the relative position of the maxillary first molar. Malocclusion refers to the misalignment of teeth and/or incorrect relation between the teeth of the two dental arches. Class I malocclusion, presents a normal molar relationship, but the other teeth have problems like spacing, crowding, over or under eruption. In Class II malocclusion, or distocclusion, the upper molars are placed not in the mesiobuccal groove but anteriorly to it. The anterior dental relation can vary, originating two subclasses: division 1, when the maxillary incisors are positioned forward to the lower incisors resulting in marked overjet; division 2, when there is linguoversion (retroversion) of the maxillary central incisors. Class III malocclusion, or mesiocclusion, refers to an advancement of the lower dental arch. Occlusal class has been shown to be directly related to articulatory perturbation of speech sounds such as fricatives. Understanding the influence of occlusal class in stomatognathic functions requires a thorough assessment of the craniofacial configuration. The size, form and relative position of the craniofacial bones may be in the origin of malocclusions and functional disorders. X-Ray Microbeam Speech Production Database (XRMB-SPD) is a speech production database, created at Wisconsin University, USA, that uses X-Ray Microbeam technology to collect a vast amount of coordinate data describing articulatory movements, and also includes acoustic and electroglotographic data collected simultaneously [3]. XRMB-SPD articulatory data are presented in a two dimensional xy mid-saggital plane that includes: palate line, posterior pharynx wall line, lips, tongue and mandible. The coordinates of each mobile structure refer to an 8 pellet system distributed through the oral cavity: lower lip, upper lip, mandibular incisor, mandibular first molar and tongue (4 pellets). The speech samples result from different tasks, including word and sentence reading, isolated productions, and non-verbal oral movements. The speaker sample includes 57 male and female speakers of American English, with an average age of 21. The database includes individual parameters characterizing each subject (e.g., dental information), which allowed us to study the relations between speech production and occlusal class. The present study was concerned with the variations of different malocclusion class subjects, namely: (a) the description of articulatory structures involved in speech production; (b) the comparison of acoustic features and articulatory processes in vowel and consonant productions; (c) the characterization of the functional adaptations found.