Thesis is focused on the impact of the inside noise of the car on conditional driver safety, which is presented by reaction times on simulated stimulus. In introduction, there is a theoretical definition of the security of the vehicles, inside noise, and its methods of measurement. Practical part consists of description and realization of the measurements of the impact on the inside noise in the car on reaction time of drivers. Conclusion includes evaluations of the measurements and findings, which results from them.

The diploma thesis deals with noise measurement. The theoretical part contains the knowledge gained by studying literature. I have described acoustics, sound and noise, noise and health and legislative contexts as well as noise reduction methods. The practical part contains information about the company and individual machinery, the results of measurements and their evaluation according to valid legislation. I have suggested appropriate measures to reduce the noise burden on operators.

The aim of this diploma paper was to characterize sound level meters by Brüel and Kjaer Company and especially to offer the description of the Type 2250 and characterization of its functions. One Type 2250 Sound Level Meter was available to the author when working on the diploma paper. This measuring instrument was used for obtaining data from measuring in several different situations. These measuring results were thereafter presented.

The diploma thesis deals with the measurement of noise from road transport. The goal of the thesis is to get acquainted with the issue of noise measurement from road traffic and the subsequent creation of noise maps. Noise measurement is carried out using Raspberry Pi.

The aim of the work is to determine noise pollution of the urban area caused by a dairy farm in Tajanov. Three receiver locations that were chosen are located on the urban area border at which are crucial for the spreading of noise into this observed area. Nine time intervals were recorded in each receiver location. The length of each time interval was one hour. Equivalent continuous sound pressure levels were quantified for each day and night reference time interval. The levels were compared with the local noise law limits and the share of the dairy farm on the total amount of noise that has been identified.

El presente trabajo de investigación tuvo como objetivo principal el estudio de los niveles de ruido dentro de los hospitales, específicamente en las áreas de recuperación del Hospital del Niño, así como una propuesta para la reducción de los niveles de ruido. La medición de los niveles de ruido se efectuó en los corredores aledaños a los ambientes de recuperación, estas mediciones se realizaron con un sonómetro calibrado adecuadamente. De esta forma fue posible la determinación de los niveles de ruido máximo y su distribución en el horario diurno. La determinación de los niveles de ruido dentro de los ambientes de recuperación no fue posible, pues estos se encontraban en uso, durante el desarrollo del trabajo de investigación; sin embargo, se determinó la distribución espacial de los niveles de ruido mediante el modelamiento de la presión sonora, usando el software SoundPLAN. Finalmente, se propuso la colocación de paneles de corcho de e=20 mm, como una técnica que permita la reducción de los niveles de ruido dentro los ambientes de recuperación. Los resultados de las mediciones mostraron que los niveles de ruido pueden alcanzar los 79.4 dBA, en los corredores aledaños a las áreas de recuperación, mientras que los niveles de ruido alcanzaron los 55 dBA, dentro de los mismos, además, el uso de paneles de corcho permitió la reducción del ruido hasta en un 21%. / El presente trabajo de investigación tuvo como objetivo principal el estudio de los niveles de ruido dentro de los hospitales, específicamente en las áreas de recuperación del Hospital del Niño, así como una propuesta para la reducción de los niveles de ruido. La medición de los niveles de ruido se efectuó en los corredores aledaños a los ambientes de recuperación, estas mediciones se realizaron con un sonómetro calibrado adecuadamente. De esta forma fue posible la determinación de los niveles de ruido máximo y su distribución en el horario diurno. La determinación de los niveles de ruido dentro de los ambientes de recuperación no fue posible, pues estos se encontraban en uso, durante el desarrollo del trabajo de investigación; sin embargo, se determinó la distribución espacial de los niveles de ruido mediante el modelamiento de la presión sonora, usando el software SoundPLAN. Finalmente, se propuso la colocación de paneles de corcho de e=20 mm, como una técnica que permita la reducción de los niveles de ruido dentro los ambientes de recuperación. Los resultados de las mediciones mostraron que los niveles de ruido pueden alcanzar los 79.4 dBA, en los corredores aledaños a las áreas de recuperación, mientras que los niveles de ruido alcanzaron los 55 dBA, dentro de los mismos, además, el uso de paneles de corcho permitió la reducción del ruido hasta en un 21%. / Tesis

[pt] Esta pesquisa de mestrado teve por objetivo desenvolver uma alternativa tecnológica de baixo custo que seja capaz de realizar medições acústicas visando suprir demandas do setor acadêmico e industrial. A preocupação em reduzir custos constituiu-se na motivação do trabalho na expectativa de que o sonômetro desenvolvido seja capaz de viabilizar projetos essencialmente de cunho social, comumente descartados pelos altos custos hoje associados a medições confiáveis e à dependência de componentes eletrônicos não disponíveis no mercado nacional. Como fundamento, o instrumento de medição proposto, projetado para fornecer a exibição remota e permitir medições precisas de formas de onda capturadas de uma fonte de microfone por meio de um servidor de áudio Jack, opera em sistema Linux embarcado. Faz uso da análise espectral para permitir a visualização da forma de onda acústica no domínio do tempo, considerando funcionalidades dedicadas consideradas essenciais para fornecer resultados de medições confiáveis, quer dos níveis de pressão sonora, quer de diferentes descritores acústicos. O sonômetro foi validado com base em resultados de uma intercomparação de medições realizadas em laboratório e no campo, tomando como referência resultados confiáveis gerados por um sonômetro comercial (CESVA SC420), calibrado por um laboratório acreditado para medições acústicas junto à Rede Brasileira de Calibração (RBC/Inmetro). / [en] This master s research aimed to develop a low-cost technological alternative capable of carrying out acoustic measurements to meet the demands of the academic and industrial sectors. The concern with reducing costs was the motivation for the work in the expectation that the sound level meter developed would also enable essentially social projects, commonly discarded due to the high costs currently associated with reliable measurements and the dependence on electronic components not available on the national market. As a foundation, the proposed measurement instrument operates on an embedded Linux system and is designed to provide a remote display and enable accurate measurements of waveforms captured from a microphone source via a Jack audio server. It uses spectral analysis to allow visualization of the acoustic waveform in the time domain, considering dedicated functionalities essential to provide reliable measurement results, whether of sound pressure levels or different acoustic descriptors. The sonometer was validated based on results from an intercomparison of laboratory and field measurements, taking as a reference reliable results generated by a commercial sound level meter (CESVA SC420) calibrated by a laboratory accredited for acoustic measurements by the Brazilian Calibration Network (RBC/Inmetro).

The aim of this work is the design and implementation of a sound level meter for emdedded systems. It is designed sound level meter sensor. This sensor includes a microphone, microphone preamplifier and ADC. This sensor is connected to a development kit STM32F4 Discovery, where sound is processed. It is processed filtration, time weighting, calculation of sound leve and loudness weighting. The sound level is then sent via the serial communication USART. This thesis includes a theoretical analysis of noise and its human perceptions. It also describes the development platform used.

La zona en estudio, ubicada entre los kilómetros 31 y 35 de la carretera Panamericana Norte, posee un nivel de presión sonora promedio de 76.48dB y 74.76dB en el horario diurno y nocturno respectivamente, y tomando como base Los Estándares de Calidad de Ruido Ambiental (ECA) se puede determinar que la zona en estudio se produce contaminación acústica. Por ello, las personas que frecuentan y/o circulan por esta zona se encuentran propensas a contraer distintas enfermedades y molestias producto de la contaminación sonora, entre ellas: Estrés, pérdida de audición con el paso del tiempo, problemas cardiológicos, entre otros. Ante lo mencionado, la presente tesis busca controlar el ruido generado por el parque automotor mediante la instalación de Barreras Acústicas en la sección vial de la Panamericana Norte, utilizando como materiales principales dos tipos de concreto, el concreto convencional y el concreto con agregados ligeros de aserrín y viruta. Para ello, el concreto con agregados ligeros de aserrín y viruta, material absorbente del sistema de Barrera Acústica, se lleva al laboratorio acústico para ensayar mediante el método del Tubo de impedancia, para obtener el coeficiente de nivel de presión sonora. Siendo este valor promedio de absorción sonora máxima de las muestras (α) 0.23. En conclusión, el sistema de barrera acústica diseñado alcanza a absorber hasta 23% del nivel de presión sonora percibido, y con ello la zona en estudio se encuentra dentro de los Estándares de Calidad de Ruido Ambiental. / The area under study, located between kilometer 31 and kilometer 35 of the Northern Pan-American Highway, has an average sound pressure of 76.48dB during daytime and 74.76dB during nighttime. Taking the Environmental Noise Quality Standards (ECA, in Spanish) into consideration, it can be determined that the noise pollution occurs in the area under study. Therefore, the people who frequent or pass by this area are prone to contract various diseases or malaise as a result, such as stress, gradual hearing loss, heart issues, among others. Given the situation, this thesis aims at controlling the noise produced by motorized vehicles by installing sound barriers on said road section of the Northern Pan-American Highway, using two types of concrete as main materials: conventional concrete and concrete with light sawdust and woodchip aggregates. The concrete with light sawdust and swarf aggregates, absorbent material of the sound barrier system, is taken to the sound laboratory to perform tests through the impedance tube method to obtain the sound pressure level. This is the average value of the maximum absorption level of the samples (α) 0.23. In conclusion, the designed sound barrier system manages to absorb up to 23% of the perceived sound pressure level. With that, the area under study falls within the Environmental Noise Quality Standards. / Tesis

This doctoral thesis focuses on noise generated during construction. It defines the legislative and physical aspects of this topic. It determines heavy machinery as noise source and categorizes them by their usage in construction technologies. It collects source data of the machinery noises which can be further used in prognostic models. It analyses the level of construction noise which can impact the nearby residential areas and offers methodology for modelling and designing the possible arrangements for the noise reduction. It defines partial effects of the construction site which are significant for the noise spreading. It establishes their role in the value of acoustic pressure level of the noise affecting the façade of the considered building. With the data collection and with case study verification it offers a prepared work tool which can be easily used to predict noise levels on construction sites and can be applied in the early constructions preparations. The structure of this thesis is planned for possible usage as university textbook or study support.