| 1. |
- Forssén, Jens, 1968, et al.
(author)
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An urban planning tool demonstrator with auralisation and visualisation of the sound environment
- 2020
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In: Proceedings of the FA2020 Conference. ; , s. 869-871
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Conference paper (peer-reviewed)abstract
- The paper presents findings from a recent project about the development of a demonstrator of an urban planning tool that includes auralised sounds as well as visualisations of sound propagation and facade noise levels linked to health impact. In urban development projects, the sound environment is one of the key elements, but often enters late in the planning process. As a result, even if the noise regulations are fulfilled, the potentially good sound environment may suffer unnecessary quality reductions. In addition, the standard ways of presenting and analysing the situations, using noise levels and noise maps, has potential for improvement, especially considering the transdisciplinary approaches to planning that are increasing in use. The tool aims to simplify the usage also at early stage planning, including scenario analysis, as well as to facilitate the urban planners' understanding of the sound environment and its effects. The paper presents results from the development of the demonstrator, reflecting on auralisation as well as on multiple aspects of visualisation including grid noise maps, health-related facade noise levels and choice of colour scales.
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| 2. |
- Thorsson, Pontus, 1974, et al.
(author)
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Vibrationsdämpande markfilter för reduktion av markvibrationer vid sprängning i bergtäkter
- 2015
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Reports (other academic/artistic)abstract
- Projektet som presenteras i denna rapport har studerat möjligheterna att dämpa markvibrationer från sprängningar med hjälp av luftfyllda hål i berg. Principen är att förändringen i materialparametrar mellan berget och luften i hålen skapar reflektion av vibrationerna. Teoretisk och praktisk litteratur visar på möjligheten att skapa destruktiv interferens mellan de olika reflexerna som kan styras till att dämpa markvibrationerna. Detta projekt har utfört praktiska fältförsök i full skala för att utreda om tekniken är möjlig att använda kring bergtäkter.De utförda provningarna i verkliga miljöer visar på att det finns möjligheter att dämpa markvibrationer genom att skapa ett metamaterial som består av borrade hål i berg. Störst effekt får man om man kan skapa tillräckligt stora hål jämfört med vibrationens våglängd. Genom att välja rätt geometri, d v s håldiameter och borrplan, kan man välja vilka frekvenser där vibrationen ska reduceras.I de praktiska försöken som genomförts i detta projekt har det visats att man kan simulera stora hål genom att borra mindre hål tätt samman inom en cirkel. Detta är ett mycket viktigt resultat då de relevanta våglängder i bergtäktsammanhang är långa, vilket kräver stora håldiametrar. De simulerade stora hålen i Glimmingen visade på en potentiell dämpning av vertikala vibrationshastigheter med omkring 50 % i frekvensbanden 100-125 Hz. Detta är stora sänkningar som bör undersökas vidare om de kan realiseras praktiskt vid befintlig bergtäkt. Vid bostäder som ligger nära bergtäkter är det vanligt att vibrationshastigheterna har högst värden vid ca 30 – 40 Hz, vilket medför att de simulerade hålen skall vara 2 – 3 gånger större än de som borrades i Glimmingen. Detta medför grupperingar av borrhål inom cirklar som är omkring 3 m i diameter.Vidare visade de praktiska försöken att effektiviteten av ett sådant filter måste utvärderas med mätningar i samma punkter före och efter ett filter har konstruerats. Annars finns risk att man attribuerar vågdämpnings- och eventuella vågförstärkningseffekter som sker i berget till filtret. Kort sagt, filtrets effektivitet utvärderas felaktigt.Innan metoden med markfilter av borrhål kan användas som ett praktiskt hjälpmedel att minska markvibrationer kring bergtäkter måste ett designverktyg skapas som kan hantera alla platsspecifika variabler.
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| 3. |
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| 4. |
- Ögren, Mikael, et al.
(author)
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Visualisation of traffic noise exposure and health impact in a 3D urban environment
- 2021
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In: Paper collection of the ICBEN 2021 Congress.
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Conference paper (peer-reviewed)abstract
- It is becoming increasingly common to work with urban planning using 3D visualisation tools. In the project DemoVirPEN a research team with participation from different research fields cooperated to create a demonstration concept for visualising traffic noise and the associated health impact in a 3D graphics environment. The project included participation from the following fields; 3D modelling and mapping, traffic noise calculation, auralisation, urban planning and architecture and health impact of noise exposure. The final product of the project is summarised in a film clip that illustrates the main results by visualising and auralising traffic in different configurations from different perspectives. A few key points are visualising short time frames (single vehicle passage) versus yearly average (noise map), and impact of changes such as removing or modifying traffic flows and buildings.
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| 5. |
- Ahrens, Jens, 1978, et al.
(author)
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Tutorial on scaling of the discrete fourier transform and the implied physical units of the spectra of time-discrete signals
- 2020
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In: 148th Audio Engineering Society International Convention.
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Conference paper (peer-reviewed)abstract
- The combination of the time-discrete property of digital signals together with the commonly employed definition of the discrete Fourier transform (DFT) can cause ambiguity when interpreting magnitude spectra with respect to the physical unit of the signal under consideration. Standardized scaling of spectra increases the comparability of frequency-domain data that are published in scientific articles or data sheets of commercial products. We present and discuss in this tutorial a collection of the most relevant scaling options for DFT spectra to yield amplitude spectra, power spectra, and power density spectra, and we illustrate how an implied physical unit of the underlying signal is reflected by the magnitude of the spectrum. The tutorial is accompanied by Matlab/Octave scripts that demonstrate the different cases.
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| 6. |
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| 7. |
- Bergman, Penny, 1982, et al.
(author)
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Perceptual validation of auralized heavy-duty vehicles
- 2015
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In: Euronoise 2015. ; , s. 769-774
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Conference paper (peer-reviewed)abstract
- Auralization is a valuable tool when evaluating the effect of traffic noise on people. The present study focuses on the validation of auralization of heavy-duty vehicles with a diesel engine. To capture the characteristics of the diesel engine a granular approach has been used. The granular approach has proven to be successful in a previous validation test examining two microphone positions around a still-standing truck. In the present study a granular approach was used to achieve pass-by noise at an artificial listening position alongside a Volvo truck (experiment 1) and pass-by noise inside an apartment (experiment 2). The aim of experiment 1 was to determine the number of interpolated sets of grains needed, in order to create a perceptually valid auralized signal. The results were used in the auralization of pass-by noise in an apartment in experiment 2. 20 and 15 participants respectively rated original recordings and auralized signals on four different attributes: realism, annoyance, and emotional response measured by valence and arousal. The results of both experiments suggest that auralizations of heavy-duty vehicles are successful and usable. It further indicates that what distinguish the auralized signals from the original recordings is mostly the arousal responses.
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| 8. |
- Dashti, Fatemeh, 1991, et al.
(author)
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Finite Element Modelling of Tunnel Shielding in Vibration Measurements of Ground-Borne Noise
- 2024
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In: Lecture Notes in Mechanical Engineering. - 2195-4356 .- 2195-4364. ; 14th International Work-shop on Railway Noise, IWRN 2022, s. 723-730
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Conference paper (peer-reviewed)abstract
- Several factors can affect vibration levels during transmission from a tunnel to the ground surface. This study investigates the effect of a tunnel cavity in bedrock with force excitation at the tunnel floor. The tunnel geometry affects the wave propagation around the tunnel and the directivity pattern of waves propagating to the ground surface. For instance, there is no direct propagation path of ground waves from the excitation in the tunnel floor to positions on the tunnel walls. The waves reaching the walls have been diffracted at the tunnel corners. This tunnel shielding effect is here investigated regarding sensor position and direction and directivity of wave propagation up to 1 kHz using the finite element method. An underground tunnel is modelled in 2D and 3D for a bedrock ground typical for Swedish conditions. The results show that the velocity levels at the tunnel floor are higher than at the tunnel wall. It is also shown that the tunnel shielding effect causes decreased vibration levels at mid-frequencies above the tunnel and significant level fluctuations, especially at higher frequencies. The results from the 3D modeling support the 2D results.
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| 9. |
- Höstmad, Patrik, 1974, et al.
(author)
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Off-peak low noise heavy-duty vehicles, facade insulation and indoor noise disturbance
- 2016
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In: Proceedings of the INTER-NOISE 2016 - 45th International Congress and Exposition on Noise Control Engineering. - 9783939296119 ; , s. 5258-5266, s. 5258-5266
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Conference paper (peer-reviewed)abstract
- Off-peak delivery of goods can result in increased transport efficiency, fuel savings, less pollution and increased traffic safety. However, unless carefully managed it causes increased annoyance and health risks for inhabitants exposed to the transportation noise during hours used for recovery and sleep. The presented work focuses on heavy-duty vehicles with Diesel engines during the "last mile" of the transport corridor through densely populated city centers. The aim is to study preconditions, open questions, and problem areas when nighttime soundscapes are altered by low noise vehicles. By using measured and simulated sounds, different driving conditions and acoustical treatments of vehicles and facade were studied at the facade and indoors in terms of 1/3-octaveband levels and judgments in listening tests. The evaluation shows that low-frequency noise of the vehicles is important indoors, while high-frequency noise is the major contributor outdoors. According to the listening tests the low-frequency noise is coupled to the degree of reported arousal, indicating that reduced low-frequency noise is especially important at nighttime. It was concluded that an acceptable indoor environment was achieved with a modified truck that is driven by a responsible driver, and by using "noise proof" windows with higher sound insulation.
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| 10. |
- Höstmad, Patrik, 1974, et al.
(author)
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Towards a low noise truck specification
- 2015
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Reports (other academic/artistic)abstract
- This report summarises the most important findings in the research project Quiter Transport for More Efficient Distribution aiming at the outline of a sound characterisation specification for noise improved heavy-duty trucks for nighttime distribution of goods. The focus in the project was on the "last mile" of the transport corridor through densely populated city centres, i.e. transport through rather narrow street canyons lined with residential housings. The noise of the loading or unloading of the goods at the destination is beyond the scope of the project. Section 2 gives the general description of the involved elements; the outdoor truck sound source, the street canyon amplification and reverberation, noise reduction by windows and facades, and the indoor noise levels due to a truck passing by in the street. Section 3 gives some specific results from the project; the results of the modifications of a truck with the purpose to reduce outdoor and indoor noise evaluated by measurements. Section 4 summarises the results of the listening clinics; including fundamental and specific results test subjects evaluating their response to real and synthesised outdoor and indoor sound of a heavy-duty truck, a light-duty van and the modified heavy-duty truck. Section 5 discusses, from various perspectives, sound attributes of a low noise truck suitable for nighttime distribution of goods. Finally, Section 6 gives the conclusions in a concise format.
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