A música ocidental é predominantemente baseada no temperamento igual, com uma razão constante 21/12 das frequências de semitom. Embora esse temperamento tenha sido usado desde o século dezenove, e apesar de seu alto grau de simetria, vários músicos têm repetidamente manifestado o seu desconforto com a harmonicidade de certos intervalos. Recentemente, foi sugerido que este problema pode ser superado através da introdução de um temperamento modificado, com uma razão de frequências constante, mas ligeiramente maior. Neste trabalho confirmamos qualitativamente esta conjectura. Usando a entropia como uma medida para a harmonicidade, mostramos numericamente que o harmônico ótimo é de fato obtido para razões de frequências ligeiramente maiores do que 21/12. Isto sugere que o temperamento igual deve ser substituído por um temperamento harmonicamente estendido, que se transformaria em novo padrão.

Western music is predominantly based on the equal temperament with a constant semitone frequency ratio of 21/12. Although this temperament has been in use since the nineteenth century and in spite of its high degree of symmetry, various musicians have repeatedly expressed their discomfort with the harmonicity of certain intervals. Recently it was suggested that this problem can be overcome by introducing a modified temperament with a constant but slightly increased frequency ratio. In this paper we confirm this conjecture quantitatively. Using entropy as a measure for harmonicity, we show numerically that the harmonic optimum is in fact obtained for frequency ratios slightly larger than 21/12. This suggests that the equal temperament should be replaced by a harmonized stretched temperament as a new standard.

Objetivo verificar quais aspectos da configuração audiométrica influenciam a discriminação de fala nas perdas auditivas neurossensoriais descendentes. Métodos foi realizado um levantamento de prontuários hospitalar dos pacientes atendidos no Serviço de Atenção à Saúde Auditiva, no período de março a julho de 2011, selecionando-se indivíduos com perdas auditivas neurossensoriais descendentes de grau leve a severo com idade superior a 18 anos. A perda auditiva foi considerada descendente quando a diferença entre as médias das frequências de 0,25 a 2 kHz e 3 a 8 kHz foi maior que 15 dBNA. A partir deste levantamento a amostra do estudo foi composta por 30 pacientes (55 orelhas) sendo 19 homens e 11 mulheres, com idades compreendidas entre 26 e 91 anos. Com base na avaliação audiológica realizada previamente, os testes de reconhecimento de fala foram correlacionados com diferentes médias de limiares tonais, incluindo as frequências de 0,5 a 4 kHz. Além disso, estudou-se as diferenças dos limiares auditivos tonais entre oitavas de frequências, ou seja, o grau de inclinação das curvas audiométricas, e o seu impacto na discriminação de fala. Resultados encontrou-se ótima correlação entre os limiares médios de 0,5 a 4 kHz com a discriminação de fala, sendo essa correlação mais forte com a inclusão das frequências de 3 e 4 kHz na média tonal. No entanto, o aumento da diferença do limiar auditivo entre as oitavas de frequências, que implica em uma maior inclinação da curva audiométrica com queda acentuada nas frequências altas, não interferiu de forma significante nos testes de reconhecimento de fala. Conclusão com base nos resultados deste estudo, pode-se concluir que as frequências de 3 e 4 kHz contribuem para a inteligibilidade de fala.

Purpose to determine which aspects of the audiometric configuration influence speech recognition in ski slop sensorineural hearing loss. Methods a survey of hospital records of patients treated at the Hearing Health Care in the period from March to July 2011 was performed selecting individuals above 18 years old and ski slop sensorineural hearing loss from mild to severe degree, with difference between the means of the frequencies of 0.25 to 2 kHz and 3-8 kHz greater than 15 dB HL. The sample of the study consisted of 30 patients (55 ears), 19 men and 11 women, aged between 26 and 91 years. Based on audiological evaluation, tests of speech recognition were correlated with different average hearing thresholds, including frequencies from 0,5 to 4 kHz. Furthermore, the differences in auditory thresholds between octave frequencies was studied and its impact on speech discrimination. Results excellent correlation was found between the mean thresholds from 0,5 to 4 kHz with speech discrimination, this correlation being stronger with the inclusion of the frequencies of 3 and 4 kHz in tone average. However, increasing the difference in hearing threshold between octaves of frequencies, which implies a ski slop, did not interfere significantly on tests of speech recognition. Conclusions based on the results of this study, we can conclude that the frequencies of 3 kHz and 4 kHz contribute to the speech intelligibility.

The specimen distribution pattern of a species can be used to characterise a population of interest and also provides area-specific guidance for pest management and control. In the municipality of Dracena, in the state of São Paulo, we analysed 5,889 Lutzomyia longipalpis specimens collected from the peridomiciles of 14 houses in a sector where American visceral leishmaniasis (AVL) is transmitted to humans and dogs. The goal was to analyse the dispersion and a theoretical fitting of the species occurrence probability. From January-December 2005, samples were collected once per week using CDC light traps that operated for 12-h periods. Each collection was considered a sub-sample and was evaluated monthly. The standardised Morisita index was used as a measure of dispersion. Adherence tests were performed for the log-series distribution. The number of traps was used to adjust the octave plots. The quantity of Lu. longipalpis in the sector was highly aggregated for each month of the year, adhering to a log-series distribution for 11 of the 12 months analysed. A sex-stratified analysis demonstrated a pattern of aggregated dispersion adjusted for each month of the year. The classes and frequencies of the traps in octaves can be employed as indicators for entomological surveillance and AVL control.

We introduce a new VEP paradigm - the Jitter Spatial Frequency (JSF) Sweep VEP - that permits efficient mapping of the spatiotemporal tuning of the developmental motion asymmetry (DMA). Vertical sinewave gratings undergoing 90º horizontal oscillatory displacements (6 or 10 Hz) were presented while their SF was swept over 2 to 5 octaves during each VEP trial. JSF sweep VEPs were recorded from 28 infants (8-43 weeks), and symmetric (second-harmonic, F2) and asymmetric (F1) components of the VEP were measured. JSF sweeps can provide four useful estimates: (1,2) the high-SF cutoff of F1 and F2 responses estimates the spatial resolution of direction-selective (DS) and non-DS mechanisms, respectively; (3) the low-SF cutoff for F1 estimate the SF-boundary between mature (F1 absent) and immature (F1 present) DS mechanisms; and (4) the F1 high-SF cutoff estimates the lower velocity limit of cortical DS cells. For 6 Hz, the low-SF F1 cutoffs increased two times faster than traditional (contrast-reversal) VEP grating acuity (0.5 vs ~0.25 octaves/month), and twice that of the high-SF F1 and F2 cutoffs. This implies that no single mechanism can account for the DMA at both low and high SFs. At 10 Hz, the DMA exhibited no significant development, consistent with slower maturation of DS mechanisms at higher ST frequencies. The F2 high-SF cutoffs were higher than F1 at both 6 and 10 Hz, suggesting higher spatial resolution for non-DS (pattern) vs DS (motion) mechanisms. Finally, the lower velocity limit of the DS mechanisms decreased from ~2 deg/sec at 8 weeks, to 0.75 deg/sec at 33 weeks, similar to analogous limits for direction-of-motion identification in adults (~0.5 - 1 deg/sec), and close to prior VEP estimates in infants (0.6 deg/sec).

OBJETIVO: Analisar acusticamente as consoantes plosivas /p, b, t, d, k, g/ e fricativas /f, v, s, z,∫,<img src="/img/revistas/rsbf/v14n3/simbZ.gif" align="absmiddle">/ do Português Brasileiro em relação às variáveis duração, frequência e variação de oitavas por segundo. MÉTODOS: A produção de palavras contendo os sons-alvo foi analisada por meio de uma prova de imitação de palavras. Cada participante, com idades entre oito e dez anos repetiram uma série de palavras isoladas retiradas de uma lista foneticamente balanceada para o Português Brasileiro. Os parâmetros analisados foram: duração do som-alvo (fricativo ou plosivo) e valores das frequências inicial e final do F2 medidos em Hz. A partir destes valores foi calculada a variação de oitavas por segundo presente no F2 de cada consoante e, posteriormente, foi realizada a média para todos os sons. RESULTADOS: Quanto à duração das consoantes, os valores variaram entre 31 ms e 170,5 ms. Em relação ao F2, os valores variaram entre 2617 Hz na frequência inicial da plosiva sonora /b/, até 4557 Hz, valor médio da frequência inicial observado na fricativa sonora /z/. Em relação à variação de oitavas por segundo presentes no F2, a maior variação foi encontrada para a plosiva surda /p/ (16,23 oitavas por segundo) e a menor para a fricativa surda /S/ (1,624 oitavas por segundo). Considerando a média para todos os sons-alvo analisados, o valor encontrado foi de aproximadamente 6,8 oitavas por segundo. CONCLUSÃO: Os valores observados serão úteis para a elaboração de testes e de treinamentos auditivos contendo estímulos auditivos não-verbais semelhantes às características temporais presentes no Português Brasileiro.

PURPOSE: To acoustically analyze the stop consonants /p, b, t, d, k, g/ and the fricatives /f, v, s, z,∫, <img src="/img/revistas/rsbf/v14n3/simbZ.gif" align="absmiddle">/ from Brazilian Portuguese, regarding the variables duration, frequency and octave variation per second. METHODS: The production of words with the target phonemes was analyzed by using an imitation task. Each participant, with age between eight and ten years, repeated a series of isolated words selected from a phonetically balanced list for Brazilian Portuguese. Words were acoustically analyzed considering duration of the target sound (stop or fricative consonant), and initial and final frequency values of F2, measured in Hz. Based on these values, the variation of octaves per second present in each consonant's F2 was calculated, as well as the average value considering all consonants analyzed. RESULTS: Consonants' duration varied from 31 ms to 170.5 ms. Values of F2 varied from 2617 Hz, for the initial frequency of the voiced stop /b/, to 4557 Hz, average value for the initial frequency of the voiced fricative /z/. Regarding the variation of octaves per second present in F2, the higher variation was found for the unvoiced stop /p/ (16.23 octaves per second), and the lower variation, for the unvoiced fricative /S/ (1.624 octaves per second). The average value found for all target-sounds analyzed was of approximately 6.8 octaves per second. CONCLUSION: The values observed in the study will be useful to the elaboration of auditory tests and trainings including nonverbal stimuli analogous to the temporal characteristics of speech in Brazilian Portuguese.

OBJETIVOS: Propor valores normativos de acuidade visual de grades e sua respectiva diferença interocular medidas pelo potencial visual evocado de varredura nos primeiros três anos de vida. MÉTODOS: Foram avaliadas 67 crianças sadias, sem doenças oculares, que tiveram a acuidade visual medida pelos potenciais evocados visuais de varredura. RESULTADOS: A acuidade visual média variou de 0,80 logMAR (equivalente de Snellen de 20/125) no primeiro mês de vida a 0,06 logMAR (equivalente de Snellen de 20/20) aos 36 meses. Os limites normais inferiores (percentil 95%) variaram de 0,95 logMAR (20/180) a 0,12 logMAR (20/25) com progressão de aproximadamente 3 oitavas nos primeiros 36 meses de vida. A diferença interocular máxima aceitável foi de 0,10 logMAR. CONCLUSÕES: Os valores normativos de acuidade visual e de diferença interocular de acuidade foram obtidos pela técnica do potencial visual evocado de varredura. Propõe-se sua adoção na prática clínica para diagnóstico preciso do estado visual de bebês e de crianças pré-verbais.

PURPOSE: To determine age norms for grating visual acuity and interocular acuity differences measured by the sweep-visually evoked potentials (VEP) technique in the first three years of life. METHODS: Monocular grating visual acuity was measured using the sweep-VEP in 67 healthy normal infants and children in the first 36 months of life. RESULTS: Sweep-VEP grating acuity ranged from 0.80 logMAR (20/125 Snellen equivalent) in the first month of life to 0.06 logMAR (20/20 Snellen equivalent) at 36 months of age. Lower normal limits (95th percentile limit) ranged from 0.95 logMAR (20/180) to 0.12 logMAR (20/25) with a progression of approximately 3 octaves in the first 36 months of age. The largest acceptable interocular acuity difference for clinical purposes was 0.10 logMAR. CONCLUSIONS: Age norms for grating acuity along with interocular acuity differences were determined using the sweep-VEP technique. These norms should be incorporated in clinical practice for precise diagnosis of visual status in infants and preverbal children.