Max de Castro Magalhães

Effect of classroom acoustics on the speech intelligibility of students

PURPOSE To analyze the acoustic parameters of classrooms and the relationship among equivalent sound pressure level (Leq), reverberation time (T₃₀), the Speech Transmission Index (STI), and the performance of students in speech intelligibility testing. METHODS A cross-sectional descriptive study, which analyzed the acoustic performance of 18 classrooms in 9 public schools in Belo Horizonte, Minas Gerais, Brazil, was conducted. The following acoustic parameters were measured: Leq, T₃₀, and the STI. In the schools evaluated, a speech intelligibility test was performed on 273 students, 45.4% of whom were boys, with an average age of 9.4 years. The results of the speech intelligibility test were compared to the values of the acoustic parameters with the help of Students t-test. RESULTS The Leq, T₃₀, and STI tests were conducted in empty and furnished classrooms. Children showed better results in speech intelligibility tests conducted in classrooms with less noise, a lower T₃₀, and greater STI values. The majority of classrooms did not meet the recommended regulatory standards for good acoustic performance. CONCLUSION Acoustic parameters have a direct effect on the speech intelligibility of students. Noise contributes to a decrease in their understanding of information presented orally, which can lead to negative consequences in their education and their social integration as future professionals.

Vocal dose in teachers: correlation with dysphonia.

Teachers are professionals with high prevalence of dysphonia, whose main risk factors are the large work hours in classrooms with the presence of background noise. The purpose of the study was to calculate the phonation time and the cycle dose of teachers with dysphonia and teachers without voice disorders during the class. There were two groups analyzed: five teachers with functional dysphonia were the first group and five teachers without voice disorders were the second group. For the data was used the VoxLog® dosimeter and the parameters were: intensity; fundamental frequency; phonation time and cycle dose. The statistical analysis used ANOVA, Students T-test, and Kruskal-Wallis test. Dysphonic teachers showed major values of phonation time and cycle dose compared with teachers without voice disorders. The dysphonia is related to extended period of speech time and greater exposure of the tissue of the vocal fold to phonotrauma.

The impact of noise exposure on workers in Mobile Support Units

PURPOSE To investigate the presence of auditory and nonauditory symptoms in professionals working in ambulances. METHODS This was a descriptive cross-sectional study with a convenience sample. Thirty-six professionals working in mobile support units, including drivers and nursing technicians from two private urgency and emergency services in the city of Belo Horizonte, Minas Gerais, Brazil, participated in the study. A questionnaire containing 17 multiple-choice questions was applied to the participants with questions regarding life history and occupation, family history of hearing loss, use of medications, and presence of auditory and nonauditory symptoms, among others. The professionals answered the questionnaire individually, in their workplaces, and received help from the researcher to understand the content of questions, if needed. Data were statistically analyzed using the Statistical Package for the Social Sciences (SPSS) software, version 16.0. RESULTS The most reported auditory symptoms were tinnitus, intolerance to intense sounds, and ear plenitude. The most reported nonauditory symptoms were irritability, headache, talking difficulties in noisy environments, and sleep alterations. A difference (p≤0.05) was observed when the relation between self-perception of drivers and nursing technicians on hearing acuity, presence of tinnitus, irritability, and communication difficulty was analyzed. CONCLUSION Auditory and nonauditory symptoms are frequent in workers from mobile support units. An association between the workers symptoms and the performed function was also observed. The results indicate a need of developing preventive actions regarding general health, which are aimed at the preservation of hearing health and quality of life of these professionals.

Dose Vocal: uma revisão integrativa da literatura

O objetivo da pesquisa foi realizar uma revisao da literatura referente aos tipos de dose vocal e aos resultados destas medidas em diferentes situacoes comunicativas. Houve levantamento da literatura nacional e internacional, publicada nos idiomas Ingles, Espanhol ou Portugues, utilizando-se as bases de dados MEDLINE, LILACS, IBECS e ISI (Web of Science), dos ultimos 21 anos, cujos artigos estavam disponiveis na integra. Quinze estudos contemplaram os criterios propostos. A maioria dos artigos estudou professores, visto que sao mais vulneraveis para a ocorrencia de disfonia. Os tipos de dose encontrados foram porcentagem de fonacao, dose temporal, dose ciclica, dose de distância, dose de energia radiada e dose de energia dissipada. O aumento da dose vocal esta associado ao uso excessivo e prolongado da voz na atividade docente, principalmente entre os professores da educacao infantil e os de canto. As altas doses vocais correlacionam-se tambem a presenca de disfonia, ao maior nivel de ruido ambiental, a grande variacao prosodica na fala e a autopercepcao de fadiga vocal. Pacientes com disfonia comportamental (nodulos e polipos) apresentam maiores doses vocais que pacientes com outros quadros disfonicos. Fatores como repouso de voz e uso do amplificador vocal indicam a diminuicao da dose da voz.

The Influence of Noise on the Vocal Dose in Women

OBJECTIVE The objective of this study was to evaluate if noise interferes with the vocal dose in women without vocal complaints. STUDY DESIGN This is an experimental and comparative study. METHODS Data were collected on 27 women between 22 and 50 years of age without vocal complaints in a university classroom. Speech-language pathology evaluation was performed employing auditory-perceptual analysis and a vocal symptom questionnaire. The acoustics of the classroom were evaluated via both observation of the characteristics of the room and the quantification of background noise and reverberation time. Two distinctive acoustic conditions were created for evaluations: condition 1, a room without acoustic treatment and without noise reproduction, and condition 2, a room without acoustic treatment with noise reproduction. Each participant was evaluated individually in both acoustic conditions. To obtain vocal dose data, a vocal dosimeter was used. Subjects were asked to perform two 10-minute readings, one in each acoustic condition. The order of conditions was randomized between subjects. Subjects were instructed to complete the reading tasks at the vocal intensity deemed appropriate to be heard by a listener in the back of the room. t Tests and the Wilcoxon test were employed to compare parameters across subjects and conditions. RESULTS Fundamental frequency, vocal intensity, percentage of phonation, and cycle dose significantly increased in the background noise condition. CONCLUSION A positive relation between vocal dose and the presence of excessive noise in the environment was observed.

A mass-spring model of the auditory system in otosclerosis

INTRODUCTION: This paper aims to describe a model to simulate otosclerosis using a mass-spring model and to correlate the results with the clinical and audiological data on the disease. METHODS: A mass-spring model was used to represent the behavior of the auditory system simulating otosclerosis. The model consisted of six masses (air volume in the external auditory canal; tympanic membrane; malleus; incus; stapes, and cochlear fluid), springs and dashpots simulating the supporting ligaments and muscles. The parameters to simulate the disease were obtained from the literature; stapedial annular ligament stiffness was increased by 10-fold and to 100-fold and stapes mass increased by 5-fold. RESULTS: There was a decrease in stapes displacement in the lower frequencies when the stiffness of the stapedial annular ligament was increased. It was also found a reduction in stapes displacement in the higher frequencies with increased stapes mass. CONCLUSION:The increased stiffness of the stapedial annular ligament can be an indication of early stage disease, whereas increased bone growth suggests disease progression. The results of the simulation are in agreement with the clinical and audiological disease and support the need for further study of the stapedial annular ligament to find ways to evaluate its functioning and thus enable early detection of hearing losses caused by changes in that structure.