The goal was to identify sound pressure level (SPL) at the neonatal intensive care unit (NICU) and inside the incubator of a teaching hospital of a public university from São Paulo -SP, Brazil. SPL inside the NICU and the incubator were measured using four dosimeters in January/2010. SPL at the NICU varied from 52.6 dBA to 80.4 dBA and inside the incubator, from 45.4 dBA to 79.1 dBA. SPL both at the NICU and inside the incubator are above the recommended values, but levels were higher at the NICU than inside the incubator.Although there are some specific factors related to SPL inside the incubator, the NICU and incubator acoustic features present a system: an increase/decrease in SPL at the NICU usually tends to increase/decrease SPL inside the incubator. The study points to the need for simultaneous monitoring of SPL at the NICU and inside the incubator. Evidenciou-se que tanto o NPS da UTIN como o do interior da incubadora estão acima dos recomendados, sendo mais altos na UTIN do que na incubadora. Embora haja alguns fatores específicos relacionados ao NPS no interior da incubadora, perfis acústicos da UTIN e da incubadora são como sistema: elevação/redução do NPS da UTIN, geralmente, tende a elevar/reduzir o NPS no interior da incubadora. Portanto, pode-se concluir que o presente estudo aponta para a importância do monitoramento simultâneo dos NPS da UTIN e do interior da incubadora.Descritores: Ruído; Terapia Intensiva Neonatal; Enfermagem Neonatal; Humanização da Assistência; Recém-Nascido. Ruido en la Unidad de Terapia Intensiva Neonatal y en el interior de la incubadoraSe tuvo por objetivo identificar el nivel de presión sonora (NPS) de la Unidad de Terapia Intensiva Neonatal (UTIN) y del interior de la incubadora de un hospital escuela de una universidad pública de Sao Paulo-SP, Brasil. El NPS de la UTIN y de la incubadora fueron obtenidos por cuatro dosímetros en enero de 2010. El NPS de la UTIN varió entre 52,6 dBA y 80,4 dBA y el del interior de la incubadora fue de 45,4dBA a 79,1dBA. Tanto el NPS de la UTIN como el del interior de la incubadora son mayores que lo que recomendado, siendo más altos en la UTIN que en la incubadora. A pesar de que existen algunos factores específicos relacionados al NPS en el interior de la incubadora, los perfiles acústicos de la UTIN y de la incubadora son como un sistema, es decir: la elevación/reducción del NPS de la UTIN generalmente tiende a elevar/reducir el NPS en el interior de la incubadora.Se concluye que muy importante la monitorización simultánea del NPS de la UTIN y del interior de la incubadora.Descriptores: Ruido; Cuidado Intensivo Neonatal; Enfermería Neonatal; Humanización de la Atención.

The accepted methods for measurement of sound insulation between rooms, audiometric cabins and other adjacent closed spaces deal with average sound pressure measurements and random sound excitation. The acoustic field can be as diffuse as found in reverberation chambers or form well-determined stationary waves in rectangular rooms. The use of random noise excitation requires averages in time to reduce the expected inherent uncertainties. The use of techniques, such as MLS or swept sine excitation, can avoid time consuming averaging processes and reduce measurement. With the advent of new front-end devices and signal analyzers it is now relatively easy to obtain acoustic transfer functions between two points in space, which can be in adjacent enclosures. With these transfer functions, it is possible to obtain the level differences, required by the international standard, as suggested in a new draft ISO document. This paper presents results obtained for the insulation of a cabin, tested in a reverberation chamber, using random noise and swept sine excitation. An analysis is given of the viability of using fewer positions of sound sources when measuring the transfer function. Repeatability tests, for both methods, are also presented.

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The Brazilian regulation for workplace noise evaluation requires a comparison between the measured noise levels and the noise limits listed on a table. The table establishes the maximum work hours per day for each measured sound level. As in some other countries, the Brazilian table shows limit values with a resolution of 1 dB(A) and considers a 5 dB(A) exchange rate. The measured uncertainty is unknown. The use of type 2 equipment for instance can mean, theoretically, a uncertainty of 3 dB(A). In Brazil it is not possible to estimate the impact of the measurement uncertainty on the costs of compensations paid due to noise exposure. It is also very difficult to assess the number of workers that are receiving unfair compensations or are not receiving any due to inaccurate noise exposition measurements. However it is possible to assure that the amount of money can reach incredible numbers in our country. This paper presents an experimental study of the uncertainty calculated on the ISO 9612 basis for different sound signals, in different workplaces, emitted by different noise sources. The main purpose is to show how important it can be to estimate the uncertainty for each measurement.

performance of several topics for buildings up to five floors. The acoustic performance is one of them. The standards are in approval process and measurements in real buildings will be necessary. Different professionals using different equipment will emit certificates establishing which levels of insulation a certain flat provides and its uncertainties. The expanded measurement uncertainty is necessary to make different measurement results comparable. The international Guide to the Expression of Uncertainty in Measurement, the ISO/IEC Guide 98 (GUM), is a widely accepted document to assess and evaluate the uncertainty of a measurement result, and was used in this work. The standards concerning sound insulation measurements are ISO 140 series and ISO 18233. Uncertainty estimates are available only for the classical technique described in ISO 140, based on repeatability and reproducibility tests performed in laboratories. Field measurements present some characteristics that can contaminate the results. Independent measurements were carried out in a single floor building using ISO 18233 specifications and the ISO/IEC Guide 98 was applied to obtain the uncertainty for measurement results of airborne sound insulation between rooms in situ.