Ryuta Kataoka

Spectral Properties and Quantitative Evaluation of Hypernasality in Vowels

A new technique for evaluating hypernasality using an acoustic approach is presented. In a preliminary study using this technique, nasal resonance was assessed in 17 normal subjects and 16 subjects judged to be hypernasal. Analyses of the one-third-octave power spectra revealed an increase in power level between the first and second formant, and a reduction in the power level in second and third formant regions among utterances judged to be hypernasal. Factor analysis of the perceptual ratings revealed that the consensus perception of hypernasality accounted for 71% of the total variance. An additional 8% was accounted for by individual differences. Multiple regression analysis revealed a high correlation between the consensus perception of hypernasality and the variance in two acoustic-power levels, these being the power level between the first and second formant and the power level of the second and third formant regions.

EFFECTS OF SURFACE ROUGHNESS AND DIMORPHISM ON THE ADHESION OF CANDIDA ALBICANS TO THE SURFACE OF RESINS: SCANNING ELECTRON MICROSCOPE ANALYSES OF MODE AND NUMBER OF ADHESIONS

AIM Candida albicans is a common oral fungus but can cause serious conditions such as Candida stomatitis. We investigated C. albicans adhesion to the surface of denture-base resins at two growth phases. METHODS Fungal suspensions of logarithmic (9 h) and stationary phase (24 h) C. albicans (JCM2085) were used. Scanning electron microscopy (SEM) confirmed that yeast and mycelial forms were predominant in 9-h and 24-h cultures, respectively. Resin strips were polished to three surface roughness levels (Ra 3.2 μm, Ra 0.48 μm and Ra 0.06 μm) and were then immersed in C. albicans suspensions for both phases. The SEM images were taken at five sites on each strip. RESULTS Adhesion of mycelial-form C. albicans on rough surfaces (Ra = 3.2) was 2.2 times higher than on smooth surfaces (Ra = 0.06; 7030 vs 3580 adhesions/mm(2), P < 0.01). The hyphae of these mycelial forms fully penetrated the surface cracks. Fewer adhesions occurred for yeast-form C. albicans, regardless of surface type (440-620 adhesions/mm(2), P = n.s.). CONCLUSION Adhesion of yeast-form C. albicans was indifferent to surface roughness. In contrast, mycelial adhesion increased with surface roughness of the resin because mycelia infiltrated the minute protuberances on rough surfaces.

Quantitative evaluation of hypernasality in cleft palate patients

To quantitatively evaluate hypernasality in cleft palate patients, the Japanese vowel /i/ pronounced by six cleft palate patients and four normal children (controls) of similar ages was analyzed acoustically by cepstrum analysis. Spectrum envelopes obtained by the cepstrum method were evaluated every 1/3 octave to obtain the mean level in each band. Ten listeners evaluated a speech sample from each subject for degree of nasality on an equal interval scale ranging from 0 (no nasality) to 4 (strongest nasality). Two factors were obtained from the factor analysis of the judged scores. The first factor, which accounted for 77% of the total variance, was the consensus perception of nasality. The second factor, which accounted for 9%, was the difference among the individual listeners. The levels in two 1/3 octave bands were highly correlated with the first factor. The central frequencies of these two bands were 1 and 5 kHz.

What did first-year students experience during their interprofessional education? A qualitative analysis of e-portfolios

ABSTRACT Interprofessional collaboration is an essential approach to comprehensive patient care. As previous studies have argued, interprofessional education (IPE) must be integrated in a stepwise, systematic manner in undergraduate health profession education programmes. Given this perspective, first-year IPE is a critical opportunity for building the foundation of interprofessional collaborative practice. This study aims to explore the first-year students’ learning processes and the longitudinal changes in their perceptions of learning in a year-long IPE programme. Data were collected at a Japanese medical university, in which different pedagogical approaches are adopted in the IPE programme. Some of these approaches include interprofessional problem-based learning, early exposure, and interactive lecture-based teaching. The students are required to submit written reflections as a formative assessment. This study conducted an inductive thematic analysis of 104 written reflections from a series of e-portfolios of 26 first-year students. The themes related to learning outcomes from student perspectives included communication (e.g., active listening and intelligible explanation), teams and teamwork (e.g., mutual engagement and leadership), roles/responsibilities as a group member (e.g., self-directed learning and information literacy), and roles/responsibilities as a health professional (e.g., understanding of the student’s own professional and mutual respect in an interprofessional team). The study also indicated three perspectives of students’ learning process at different stages of the IPE, i.e., processes by which students became active and responsible learners, emphasised the enhancement of teamwork, and developed their own interprofessional identities. This study revealed the first-year students’ learning processes in the year-long IPE programme and clarified the role of the first-year IPE programme within the overall curriculum. The findings suggest that the students’ active participation in the IPE programme facilitated their fundamental understanding of communication/teamwork and identity formation as a health professional in interprofessional collaborative practice.

The relationship between spectral properties and perceptual evaluation of hypernasality in children with cleft palate—vowel /i/

The purpose of this study was to examine the relationship between spectral characteristics and the perceptual evaluation of hypernasality in speakers with cleft palate. Speech samples from 32 cleft palate patients (average age 9.3 years) and 5 normal subjects (average age 9.4 years) were used in this study. The isolated vowel /i/ produced by each subject was filtered using 16 one‐third octave bandpass filters from 200 Hz to 6.3 kHz to obtain a 1/3 octave spectrum. These spectra were normalized using the total power level of the 16 1/3 octave bands. Three sophisticated listeners rated the speech samples using a six‐point equal‐appearing interval scale. Average spectra obtained from the hypernasal and the normal groups were compared. Spectral characteristics of hypernasality in the vowel /i/ were identified as a rise in power level between the first formant (F1) and the second formant (F2) and a rise in power level of F1. Multiple regression analysis revealed a high correlation (r=0.81) between the averaged...

Development of a microcomputer based system for evaluating hypernasality in vowels of cleft palate patients

To evaluate hypernasality quantitatively, frequency analyses were performed on the Japanese isolated vowel /i/ produced by sixteen cleft palate patients with or without speech appliances and four normal subjects. These 26 speech samples were rated by 20 listeners. Analysis of the one‐third‐octave power spectra revealed an increase in power level between the first and second formant and a reduction in second and third formant regions among hypernasal speech samples. Factor analysis of the five‐point listener’s ratings revealed that the consensus perception of hypernasality accounted for 75% of the total variance. Multiple regression analysis revealed a high correlation (0.82) between the perception of hypernasality and the peak levels of two clusters of 1/3‐octave bands: the sixth, seventh, and eighth 1/3‐octave multiples, and the tenth, eleventh, and twelfth multiples from the band containing the fundamental frequency. Based on these findings, a system for evaluating hypernasality was developed using a co...