3718 Uppsatser om Noise level - Sida 1 av 248

Induktiv provning av ferritiskt rostfritt stå

The report examines the factors which may be a contributing cause to the problems that are present when ferritic stainless steel are eddy current tested in a warm condition. The work is carried out at Fagersta Stainless AB in Fagersta which manufactures stainless steel wire. In the rolling mill there is an eddy current equipment for detection of surface defects on the wire. The ferritic stainless steels cause a noise when testing and this noise complicates the detection of defects.Because of this, a study was made of how the noise related to factors such as steel grade, temperature, size and velocity. By observing the signal and with the possibilities to change the equipment settings the capability to let a signal filter reduce the Noise level were evaluated.

Bullertunneln : En utredning kring en ny bullerlösning vid trafikleder

The purpose of this Master Thesis has been to investigate the possibilities for a new type of noise reduction solution that could decrease the negative effects resulting from larger traffic roads. The idea has been to construct a noise barrier with a roof ? like a tunnel placed on a road. The choice of material has been focused on transparent materials in order to lower visual intrusion and barrier effects. This project idea is called the Noise tunnel.After having investigated the current offer of noise solutions, it has been concluded that these solutions rarely provide a sufficient level of noise reduction ? at least not when government regulations of acceptable Noise levels are applied.

Bullerreduktion av hytt på Volvodumprar : Undersökning, mätning och analys

Too high levels of noise lead to various health problems and cost society billions of SEK peryear. In this thesis we have examined a model of the A40E articulated hauler at VolvoConstruction Equipment in Braås. We have tried to reduce cabin noise in an articulated hauler,while also providing a way on how to proceed with a machine when the cabin does not measureup to the sound requirement. The best way to find leaks were with a reference source of model4205 and its speaker HP 1001 from Brüel & Kjaer in the cab and then walk around and listen towhere the reference source was more prominent. In this way, we found that the edges and theplugs were sensitive areas.

Bulleremissioner från vertikalaxlade vindkraftverk

Wind power in Sweden is expanding in response to the government's decision that 49% of Sweden's power should originate from renewable energy sources by the year 2020. Problems with noise and sound emissions related to wind turbines are a constant argument against the wind power expansion and this paper means to examine if vertical axis wind turbines might be a viable alternative to the conventional horizontal design for noise sensitive areas. In order to determine factors like difference in frequency, noise propagation and noise emission level, measurements of both horizontal and vertical axis wind turbines have been completed and the data analyzed with MATLAB. It is shown that there is a difference in how the noise from the two types of turbines propagates due to avariation in the frequency spectra of the emitted sound. It is also shown that vertical axis wind turbines generate a lower sound emission with less intensity inthe lower frequencies..


Detta arbete handlar om noise och hur det påverkar människans arbetsminne. Den litterära bakgrunden presenterar vad noise är, hur noise fungerar som musik samt en generell överblick över minne och arbetsminnet. Problemet som undersöktes var om noise kunde påverka förmågan att tillgodogöra sig visuell information mer än vad vitt brus gjorde. För att få ett svar på frågan skapades två versioner av ett enkelt spelmoment där testpersonerna, indelade i två grupper, fick se en siffersekvens som sedan skulle skrivas ner. Samtidigt spelades i spelmomentet antingen noise eller vitt brus upp.

Åtgärder för att minimera trafikbullers påverkan på ett rekreationsområde

The aim of this inquiry was to investigate the most appropriate measures to reduce noise impacts from road traffic on the Nydala recreational area in Umeå municipality due to the planned re-routing of the E4 motorway to an existing road along this area. The sound environment is an important part in the experience when we are visiting recreational areas. Noise is not only disturbing; the liberty from unwanted sounds also allows us to perceive natural sounds that are a benefit for the cultural experience. Therefore it is important to take actions to protect this well used area from traffic noise. The reasonable options to avoid noise impact in this case are to lower the speed limit, using a noise reducing coating or use noise protection screens and walls.

Buller : Hur planeras en bullerfri stad?

Milosevic, S. 2014. Buller ? Hur planers en bullerfri stad?. Kulturgeografiska institutionen, Uppsatser, Uppsala universitet. This essay is about noise pollution caused by urbanization.

Riskerar tatuerare hörselnedsättning i arbetet?

Purpose: To examine the hearing environment for tattoo artists regarding occupational noiseand to see whether tattoo artists are exposed to hazardous noise according to Swedish WorkEnvironment Authority regulations. Method: Using a dosimeter we measured a total ofseven sessions of approximately one hour on seven different subjects, located on five studiosin Gothenburg. As a complement we did also hand out surveys based on twelve questions toexamine habits, experienced sound environment and to see if there were any hearing relatedpatterns. Results:. Sound level measurements showed that the lower exposure action valueLpAeq,8h 80 dB(A) in one case was reached if applied to the average working time of sixhours.

Bakgrundsbrusets effekt på kognitiv prestation samt skapandet av falska minnen : Om bullrets inverkan i öppna kontorsmiljöer

This study aimed to explore how 31 collage students' cognitive performance and their ability to create false memories were affected by the exposure of an extraneous background noise. The studies main hypotheses were based on previous research on how extraneous noise affect the cognitive ability and the creation of false memories: 1) that an extraneous background noise increases the ability to create false memories, 2) that an extraneous background noise impairs the learning of cognitive information, 3) that an extraneous background noise contributes to an increased representation of fictional words, 4) that an extraneous background noise impedes the ability to understand speech . The results showed a tendency in which false memories increased in the condition without background noise, a result which goes in the opposite direction of the hypothesis. Furthermore, the result supported the hypothesis that the extraneous background noise impairs the learning of cognitive information. The results also showed that there was no effect between the conditions regarding the representation of fictional information.

Oljudens musik : En revolution i kompositionsteknik?

Noise music is created around sounds not often welcome in a musical context. Since the birth of electronic music in the 1950s a new perspective on composing has emerged. In electronic music, sounds and their timbre are as much important as melody, harmony and rhythm. This composing perspective is not often observed. Therefore I have examined a musical genre that stretches the boundaries of what we consider music, sound, noise, beautiful and terrible.


The public interest in central living in today?s cities has led to an increasing effect of traffic noise pollution, and today 20% of the inhabitants in Sweden suffer from noise a level that exceeds the limits. At the same time the traffic keeps increasing, and recent researches shows that traffic noise pollution and several of today?s most common health issues are connected, for example, reduction of performance, sleeping issues and cardiovascular diseases. For this cause rules, guidelines and environmental goals has been developed, as well as software?s which calculates the levels of pollution, all this to investigate and improve the environment.

Undersökning av ljudnivåer på skolgårdar : - samt hur fasad och fönster dimensioneras med uppmätta värden

This report is written on commission by WSP Acoustics. The report studies the outdoor sound levels on school yards in Stockholm. The questions given by the company to be answered was what are the actual sound levels at diffrent school yards with low traffic noise and how can you construct a facade element that reduces the sound level from the outside and meet the indoor requirements. Mesurements for four hours was done at eight schools set north and south of the city centre. The measurement period included one school break and one lunch break.

Taluppfattningstest med enstaviga ord i brus: Normalvärden för barn i åldrarna 7, 10 och 13 år

Background: Phonemically balanced word lists are used when obtaining speech recognition scores in noise. These lists are designed for adults, but are still used for children. To properly obtain speech recognition scores in noise for children, normative data is needed to show what differences there are to be expected between children of different ages. Purpose: The main purpose is to obtain normative data for children in the ages of 7, 10 and 13 years for speech recognition scores in noise using words and to compare these with each other and with normative data of adults. A further purpose is to examine if there is any practice- or exhaustion effect to be seen when obtaining speech recognition scores in noise for children in the ages of 7, 10 and 13 years.Material: The participants were ten 7-year-olds, ten 10-year-olds and ten 13-year-olds.

Skalning och brusberäkning av tvåportsadaptorer

The goal of this work is to summarize the calculations for scaling and noise of twoportadaptor. Two different methods has been described and used for the final results..

Akustiskt åtgärdsprojekt av en rockmusikklubb där live-musik spelas. Vad kan en audionom bidra med?

Introduction: The number of hearing impairments in Sweden is increasing. The largest increase is seen in ages 25-44. There are reasons to believe that these impairments are noise induced. Leisure time noise is not controlled in the same manner that industrial noise is. An ongoing conflict between city council officials and rock club owners, musicians and music event organizers about sound levels at smaller live music clubs exceeding the national sound level restrictions created the need for an acoustic intervention project.

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