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.

No description available.

[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 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.

This work seeks to more fully characterize how the representation of English vowels changes with increasing sound level in the frequency following response (FFR) of normal-hearing adult subjects. It further seeks to help inform the design of brain-computer interfaces (BCI) that exploit the FFR for hearing aid (HA) applications. The results of three studies are presented, followed by a theoretical examination of the potential BCI space as it relates to HA design. The first study examines how the representation of a long vowel changes with level in normal hearing subjects. The second study examines how the representation of four short vowels changes with level in normal hearing subjects. The third study utilizes machine learning techniques to automatically classify the FFRs captured in the second study. Based in-part on the findings from these three studies, potential avenues to pursue with respect to the utilization of the FFR in the automated fitting of HAs are proposed. The results of the first two studies suggest that the FFR to vowel stimuli presented at levels in the typical speech range provide robust and differentiable representations of both envelope and temporal fine structure cues present in the stimuli in both the time and frequency domains. The envelope FFR at the fundamental frequency (F0) was generally not monotonic-increasing with level increases. The growth of the harmonics of F0 in the envelope FFR were consistent indicators of level-related effects, and the harmonics related to the first and second formants were also consistent indicators of level effects. The third study indicates that common machine-learning classification algorithms are able to exploit features extracted from the FFR, both in the time and frequency domains, in order to accurately predict both vowel and level classes among responses. This has positive implications for future work regarding BCI-based approaches to HA fitting, where controlling for clarity and loudness are important considerations.

<p>Disertacija obuhvata opis osnovnih pojmova i metoda merenja iz oblasti muzičke akustike, detaljnije razrađeni teorijski model pona&scaron;anja zvučnog talasa u cevi frule i detaljnu analizu frekvencijskog spektra tonova odsviranih na jednodelnim i dvodelnim frulama, na glavi dvodelnih frula i tonova dobijenih upotrebom različitih vrsta prigu&scaron;ivača.</p> / <p>The dissertation presents a description of the Musical acoustics basic facts and<br />measuring methods , a profoundly developed theoretical model of behaviour of sound waves in sheperd&#39;s flute, and very detailed frequency spectrum analysis of musical tones played on simple Serbian flute, two-piece Serbian flute, tones played only on the had of the flute and musical tones played on the two-piece Serbian flute using different typesof mutes.</p>

For many undersea research application scenarios, instruments need to be deployed for more than one month which is the basic time interval for many phenomena. With limited power supply and memory, management strategies are crucial for the success of data collection. For acoustic recording of undersea activities, in general,either preprogrammed duty cycle is configured to log partial time series,or spectrogram of signal is derived and stored,to utilize the available memory storage efficiently.To overcome this limitation, we come up with an algorithm to classify different and store only the sound data of interest. Features like characteristic frequencies, large amplitude of selected frequencies or intensity threshold are used to identify or classify different patterns. On main limitation for this type of approaches is that the algorithm is generally range-dependent, as a result, also sound-level-dependent. This type of algorithms will be less robust to the change of the environment.One the other hand, one interesting observation is that when human beings look at the spectrogram, they will immediately tell the difference between two patterns. Even though no knowledge about the nature of the source, human beings still can discern the tiny dissimilarity and group them accordingly. This suggests that the recognition and classification can be done in spectrogram as a recognition problem. In this work, we propose to modify Principal Component Analysis by generating feature points from moment invariant and sound Level variance, to classify sounds of interest in the ocean. Among all different sound sources in the ocean, we focus on three categories of our interest, i.e., rain, ship and whale and dolphin. The sound data were recorded with the Passive Acoustic Listener developed by Nystuen, Applied Physics Lab, University of Washington. Among all the data, we manually identify twenty frames for each cases, and use them as the base training set. Feed several unknown clips for classification experiments, we suggest that both point-based feature extraction are effective ways to describe whistle vocalizations and believe that this algorithm would be useful for extracting features from noisy recordings of the callings of a wide variety of species.

Garso lygio matavimai Šiaulių mieste buvo atlikti geguţės mėnesį. Tyrimų vietos buvo pasirinktos gyvenamojoje aplinkoje prie didţiųjų prekybos centų „Akropolis“, „Tilţė“, „Bruklinas“ ir „Saulės miestas“, gyvenamojoje aplinkoje prie geleţinkelio stoties, Šiaulių reabilitacijos centro aplinkoje, prie J. Janonio gimnazijos, kuriai didţiausią triukšmą sukelia autotransportas ir šalia Jovaro progimnazijos. Palyginimui, tose pačiose vietose matavimai buvo ir savaitgalio metu. Didţiausias ekvivalentinis garso lygis išmatuotas šalia prekybos centro „Saulės miestas“. Aukštas triukšmo lygis uţfiksuotas taip pat prie J. Janonio gimnazijos.. Vidutinis triukšmo lygis šalia gyvenamųjų namų išmatuotas netoli prekybos centrų „Tilţė“, „Akropolis“, „Bruklinas“ bei Jovaro progimnazijos aplinkoje, kuriuose garso lygiai viršija leistiną ribą 1 - 4 dBA. Šiaulių reabilitacijos centro aplinkoje neleistinų viršijimų nebuvo aptikta. Savaitgalio matavimuose didţiausias ekvivalentinis garso lygis buvo išmatuotas prie prekybos centro „Saulės miestas“. Gyvenamojoje zonoje prie geleţinkelio stoties ekvivalentinis garso lygis, lyginant su autotransporto skleidţiamais lygiais viršijamas net 12 dBA. / Sound levels were measured in month of May. Research test sites were near residential areas next to shopping centres „Saulės miestas“, „Bruklinas“, „Akropolis“, „Tilţė“, also in residential area near city railway station, in Šiauliai rehabilitation centre area, nearby J.Janonis gymnasium, whereat majority of noise is caused by motor transport, and next to Jovaras progymnasium. In comparison all the measurements have been conducted also in weekend. Highest equivalent sound level was measured near J. Janonis gymnasium. Average sound levels were detected in residential areas near shopping centres „Tilţė“, „Akropolis“, „Bruklinas“ and also in Jovaras progymnasium area, in which the equivalent sound level was exceeded by 1-4 dBA respectively. The sound levels in area near Šiauliai rehabilitation centre did not exceed the limits. The results that were conducted in weekend showed that the highest equivalent sound level was measured near the shopping centre „Saulės miestas“. Utmost sound level was measured near the railway station, where equivalent sound level was exceeded by 12 dBA. Specific noise of the railway transport is the major cause for it.

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.