RESUMEN
OBJECTIVE: The objective of this study was to compare the effects of a single-band envelope cue as a supplement to speechreading of segmentals and sentences when presented through either the auditory or tactual modality. DESIGN: The supplementary signal, which consisted of a 200-Hz carrier amplitude-modulated by the envelope of an octave band of speech centered at 500 Hz, was presented through a high-performance single-channel vibrator for tactual stimulation or through headphones for auditory stimulation. Normal-hearing subjects were trained and tested on the identification of a set of 16 medial vowels in /b/-V-/d/ context and a set of 24 initial consonants in C-/a/-C context under five conditions: speechreading alone (S), auditory supplement alone (A), tactual supplement alone (T), speechreading combined with the auditory supplement (S+A), and speechreading combined with the tactual supplement (S+T). Performance on various speech features was examined to determine the contribution of different features toward improvements under the aided conditions for each modality. Performance on the combined conditions (S+A and S+T) was compared with predictions generated from a quantitative model of multi-modal performance. To explore the relationship between benefits for segmentals and for connected speech within the same subjects, sentence reception was also examined for the three conditions of S, S+A, and S+T. RESULTS: For segmentals, performance generally followed the pattern of T < A < S < S+T < S+A. Significant improvements to speechreading were observed with both the tactual and auditory supplements for consonants (10 and 23 percentage-point improvements, respectively), but only with the auditory supplement for vowels (a 10 percentage-point improvement). The results of the feature analyses indicated that improvements to speechreading arose primarily from improved performance on the features low and tense for vowels and on the features voicing, nasality, and plosion for consonants. These improvements were greater for auditory relative to tactual presentation. When predicted percent-correct scores for the multi-modal conditions were compared with observed scores, the predicted values always exceeded observed values and the predictions were somewhat more accurate for the S+A than for the S+T conditions. For sentences, significant improvements to speechreading were observed with both the auditory and tactual supplements for high-context materials but again only with the auditory supplement for low-context materials. The tactual supplement provided a relative gain to speechreading of roughly 25% for all materials except low-context sentences (where gain was only 10%), whereas the auditory supplement provided relative gains of roughly 50% (for vowels, consonants, and low-context sentences) to 75% (for high-context sentences). CONCLUSIONS: The envelope cue provides a significant benefit to the speechreading of consonant segments when presented through either the auditory or tactual modality and of vowel segments through audition only. These benefits were found to be related to the reception of the same types of features under both modalities (voicing, manner, and plosion for consonants and low and tense for vowels); however, benefits were larger for auditory compared with tactual presentation. The benefits observed for segmentals appear to carry over into benefits for sentence reception under both modalities.
Asunto(s)
Señales (Psicología) , Lectura de los Labios , Percepción del Habla , Tacto , Adulto , Percepción Auditiva , Femenino , Humanos , Fonética , Percepción VisualRESUMEN
In manual-cued speech (MCS) a speaker produces hand gestures to resolve ambiguities among speech elements that are often confused by speechreaders. The shape of the hand distinguishes among consonants; the position of the hand relative to the face distinguishes among vowels. Experienced receivers of MCS achieve nearly perfect reception of everyday connected speech. MCS has been taught to very young deaf children and greatly facilitates language learning, communication, and general education. This manuscript describes a system that can produce a form of cued speech automatically in real time and reports on its evaluation by trained receivers of MCS. Cues are derived by a hidden markov models (HMM)-based speaker-dependent phonetic speech recognizer that uses context-dependent phone models and are presented visually by superimposing animated handshapes on the face of the talker. The benefit provided by these cues strongly depends on articulation of hand movements and on precise synchronization of the actions of the hands and the face. Using the system reported here, experienced cue receivers can recognize roughly two-thirds of the keywords in cued low-context sentences correctly, compared to roughly one-third by speechreading alone (SA). The practical significance of these improvements is to support fairly normal rates of reception of conversational speech, a task that is often difficult via SA.
Asunto(s)
Equipos de Comunicación para Personas con Discapacidad , Sordera/rehabilitación , Gestos , Procesamiento de Lenguaje Natural , Percepción del Habla , Medición de la Producción del Habla/métodos , Adulto , Niño , Simulación por Computador , Señales (Psicología) , Presentación de Datos , Humanos , Lectura de los Labios , Cadenas de Markov , Modelos Biológicos , Lengua de Signos , Inteligibilidad del Habla , Interfaz Usuario-ComputadorRESUMEN
Fluorimetric determination of selenium in colostrum, transitional and mature human milk gave the following concentrations (mean and standard deviation): 41 +/- 16, 23 +/- 6 and 17 +/- 3 ng Se ml-1, respectively. The ranges for each kind of milk, especially for mature milk, were narrow. For all cases studied, the Se concentration in milk decreased with lactation time, reaching a plateau, at 17 ng Se ml-1, after 20 days. It is estimated that breast-fed-only babies in Greece receive approximately 5-11 micrograms Se day-1 up to 6 months of age. From consumed food data it was estimated that adult Greeks receive 100 +/- 6 micrograms Se day-1, in close agreement with our previously determined value of 110 micrograms Se day-1 estimated from food disappearance data.
Asunto(s)
Dieta , Leche Humana/química , Selenio/análisis , Adulto , Lactancia Materna , Niño , Calostro/química , Femenino , Análisis de los Alimentos , Grecia , Humanos , Lactante , Recién Nacido , Lactancia , Masculino , EmbarazoRESUMEN
The Se status of 177 Greek cancer patients has been assessed by fluorimetric analysis of the Se concentration in whole blood, urine (morning) and hair. Patients either with newly diagnosed cancers or with metastases or who are undergoing therapy have statistically significant less blood, urine and hair Se than age- and sex-matched healthy controls. There is a strong and significant correlation between blood and urine or hair Se in the newly diagnosed cancers. In cancers of systems involving absorption, metabolism and excretion of Se, and in female breast cancer, the Se levels in blood, urine and hair are significantly lower than in the controls. In cancers of the respiratory and haematologic systems, blood and urine Se are normal, while hair Se is significantly lower than in controls. The results are compared with literature data; conflicting data may be due to different dietary habits of the various populations. Some cancerous tissues, such as those of the peptic system, accumulate Se compared with their adjacent, apparently healthy tissues, but others, of the urinary system for example, do not. The reason(s) for this behaviour, however, is not known.
Asunto(s)
Neoplasias/metabolismo , Selenio/deficiencia , Adolescente , Adulto , Anciano , Niño , Preescolar , Femenino , Grecia , Cabello/análisis , Humanos , Masculino , Persona de Mediana Edad , Estado Nutricional , Especificidad de Órganos , Selenio/sangre , Selenio/orinaRESUMEN
The nutritional selenium status of apparently healthy Greeks has been assessed by measuring fluorimetrically the selenium content of whole blood, morning urine, hair and finger nails. The means and standard deviations were 165 +/- 33, 25 +/- 7 ng Se ml-1, 416 +/- 86, and 536 +/- 91 ng Se g-1, respectively. No significant difference was found between the selenium content of whole blood, hair and finger nails, but, for morning urine, there was a significant difference between males and females. The young and the elderly have less selenium in these biological materials than other Greeks. Whole blood selenium correlates significantly with morning urine, hair, and finger nail selenium, as does hair and nail selenium of male, female and male + female Greeks. The results are compared with those in the literature and possible explanations for the observations are presented. It is concluded that the selenium status of Greeks is satisfactory.
Asunto(s)
Estado Nutricional , Selenio/análisis , Adolescente , Adulto , Anciano , Envejecimiento/metabolismo , Niño , Preescolar , Femenino , Grecia , Cabello/análisis , Humanos , Lactante , Recién Nacido , Masculino , Persona de Mediana Edad , Uñas/análisis , Selenio/sangre , Selenio/orina , Factores SexualesRESUMEN
The selenium content of hard and soft wheat, barley, oats, rye and corn grown in approximately 100 different locations of Greece has been determined fluorimetrically. The mean values +/- SD for these cereal types were 0.29 +/- 0.19, 0.21 +/- 0.12, 0.16 +/- 0.10, 0.14 +/- 0.10, 0.19 +/- 0.10 and 0.12 +/- 0.08 ppm Se (dry weight basis), respectively. Based on data for selenium in corn from 96 different locations, a geobotanic map of Greece for the selenium in soil available for uptake by plants was prepared. Macedonia, West Epirus, south-east Thessaly, north-east Sterea Hellas and the Aegean Islands produce corn deficient or low in selenium, but only sporadic selenium-deficiency diseases in animals have been observed in many of these areas, probably because the farm animals are given mixed food or they are free to graze. No areas with toxic levels of selenium in soil were found.
Asunto(s)
Grano Comestible/análisis , Selenio/análisis , Geografía , Grecia , Hordeum/análisis , Secale/análisis , Suelo/análisis , Zea mays/análisisRESUMEN
The total selenium concentration in various waters from all over Greece was determined fluorimetrically. The concentration in most of the drinking water, either from the tap or bottled, was within the range 100-200 ng l-1 and showed no great seasonal fluctuations. Most Greeks receive 0.2-0.4 micrograms selenium per day from drinking water. Coastal surface water contains 100-250 ng Se l-1, while higher concentrations are found at locations regarded as polluted.