Densification around railway stations and near infrastructure can lead to benefits from the climate and resource efficiency point of view. Living near infrastructure nodes can reduce car dependency and enable more sustainable travel. At the same time, noise from rail traffic causes annoyance and negative health effects for residents, and densification can therefore lead to an increase in the number of people exposed to noise, with increased social costs as a result.

The purpose of the project is to facilitate the implementation of noise measures in the infrastructure at railway stations, thereby enabling climate smart and sustainable densification in public transport-related locations, as well as efficient use of resources at the source. The goal is to compile a digital toolbox with methodology and sample collection for demonstration of technical noise-reducing measures in railway infrastructure.

The digital toolbox contains auralization of different track-close noise measures for different train types, which can be used as a complement to traditional noise predictions to create a more realistic experience of the sound environment. The auralizations are based on recordings of train passages in station-close locations, which have been corrected with calculated insertion losses for the various measures.

In addition, the socio-economic costs of noise and the corresponding benefits for a noise measure are calculated using updated valuation models based on WHO's latest recommendations. The results are compared with the current official Swedish valuation model ASEK.

The project uses co-creation to develop the tool where design and content are prioritized at a workshop together with the intended target group. The tool is openly available and an executable version for PC can be downloaded via https://sourceforge.net/projects/ljudmiljo-i-stationssamhallen/. The source code is openly accessible via https://github.com/larssonkrister/Stationsnara/.

Förtätning runt stationer och nära infrastruktur kan leda till fördelar ur klimat- och resurseffektivitetsynpunkt. Att bo i närheten av infrastrukturnoder kan minska bilberoendet och möjliggöra mer hållbara resor. Samtidigt orsakar buller från järnvägstrafiken störningar och negativa hälsoeffekter för de boende och förtätningen kan därför leda till att antalet exponerade för buller ökar, med ökade samhällskostnader som följd.

Projektets syfte är att underlätta implementeringen av bulleråtgärder i infrastrukturen vid järnvägsstationer och därigenom möjliggöra klimatsmart och hållbar förtätning i kollektivtrafiknära lägen, samt effektivt resursutnyttjande av åtgärder vid källan. Målet är att sammanställa en digital verktygslåda med metodik och exempelsamling för demonstration av tekniska bullerdämpande åtgärder i järnvägsinfrastruktur.

Den digitala verktygslådan innehåller auralisering av olika spårnära bulleråtgärder för olika tågtyper, vilket kan användas som komplement till traditionella bullerberäkningar för att skapa en mer realistisk upplevelse av ljudmiljön. Auraliseringarna är baserade på inspelningar av tågpassager i stationsnära lägen, vilka har korrigerats med beräknade insättningsdämpningar för de olika åtgärderna.

Dessutom beräknas de samhällsekonomiska kostnaderna för buller och motsvarande nyttor för en bulleråtgärd med hjälp av uppdaterade värderingsmodeller baserade på WHO:s senaste rekommendationer. Resultaten jämförs med den nu gällande officiella värderingsmodellen ASEK.

Projektet använder sig av co-creation för att utveckla verktyget där utformning och innehåll prioriteras vid en workshop tillsammans med den tänkta målgruppen. Verktyget är öppet tillgängligt och en exekverbar version för PC kan laddas ner via https://sourceforge.net/projects/ljudmiljo-i-stationssamhallen/. Källkoden är öppet tillgänglig via https://github.com/larssonkrister/Stationsnara/.

Measurement and modeling of low frequency ground reaction forces (GRFs) from human walking have been the subjects of research in different fields from biomechanics to civil engineering and structural dynamics. Many of the existing models are developed based on experiments which alter natural walking by for example presence of force transducers, limitations in the speed and path of walking and replacing the real floor with a transducerfacilitated measurement rig. These alterations result in contact forces which do not represent real GRFs. In this study, a time-domain inverse measurement method based on LMS algorithm is used to measure low-frequency (<100 Hz) forces induced by human footsteps. The LMS-based force identification method is first validated for low-frequency excitations with less complexity in number of excitation positions and frequency content compared with the footsteps. The method is then applied to measure ground reaction forces created by human walking.

In a situation where traffic, railway or aircraft noise sources are not present, as it happens in shielded areas, other sources might become relevant in terms of annoyance. This is the case of typical turbomachinery elements, such as fans, compressors or turbines, where sound is generated aerodynamically. As a part of the Sonorus project, where all noise sources in urban environments are considered, the goal of this research is to develop an auralization tool that generates a time domain signal depending on the fan working conditions and the propagation scenario. In this paper, a computational aero-acoustics solver is used to simulate the flow field generated by an axial fan, and the acoustic field is calculated using the Ffowcs-Williams and Hawkings method. The information contained in this acoustic field is used to generate an audio signal for auralization purposes. The model results are evaluated by comparisons with recordings and measurements.

New recommendations for environmental noise levels have been issued in Sweden. The permissible levels at facades of new buildings have been increased, which has resulted in a risk for higher indoor low frequency noise levels, since the recommended indoor levels are A-weighted. The additional Swedish low frequency third octave band requirements might be violated. Therefore, there is a need for reviewing how well façade insulation properties are manifested in measurements, and how accurate the measurement results indicate the indoor noise situation from the residents' perspective. In this paper, the results of façade insulation measurements are compared with corresponding models, with a special attention to associated challenges (e.g. to establish representative microphone positions in low frequency sound fields). The measurements are performed in a demonstrator house, which replicates a modern single family house. The models are evaluated both with respect to the total sound energy integrated over the entire room volumes, and as sampled sound fields, where the sample points may correspond to microphone positions. The congruence of the measured and the modelled results are analysed and discussed, as well as the relevance of different approaches.

Despite many advantages of wooden buildings, low-frequency noise disturbance, mainly from human footsteps on timber floors, is a major hindrance for widespread application of wood in multi-storey buildings. In many cases the impact noise evaluations of the wooden floors according to ISO 140-7 and ISO 717-2 standards do not correspond to subjective experiences. This study aims to investigate the characteristics of footstep forces to support further studies related to discrepancies between standard evaluations and low-frequency noise disturbances in lightweight buildings. Transient footstep forces in vertical direction made by different walkers and different footwear on two floor structures were measured and compared. The vertical footstep forces were then compared with the impact forces made by a standard tapping machine. Analysis revealed that footstep forces contain large amplitudes at low frequencies (20 < f < 50) which are not included in the standard evaluation procedure. Therefore, by extending the frequency range of the standard measurements down to 20 Hz and designing an accurate adaptation term for evaluations, a better correlation between standard impact noise evaluations and acoustic performance of the lightweight buildings might be achieved.

Social benefit calculations of reduced noise from electric bus transport in Gothenburg

In this study we examine noise from different types of buses. The aim is to calculate the economic benefits of electric buses over other bus types used in Gothenburg in terms of noise reduction. Since there is no established method to investigate the economic effects of noise from buses a large part of this study focuses on if methods currently available to quantify the health effects and economic costs of noise are sufficient to assess the effects of noise from buses. DALYs is a measure that has been developed by the World Health Organization (WHO) to quantify the health effects by counting the number of healthy life years lost every year because of the noise. ASEK is a Swedish method used to calculate the costs caused by the transport sector to society every year.

In order to calculate noise from buses in a sufficiently correct way, it is necessary to have knowledge on how the different bus types operating in Gothenburg today sound. In Gothenburg there are diesel, gas, hybrid and electric buses. The method we used to calculate the bus noise was Nord2000, which is a more advanced method of calculation than the one usually used for calculations in Sweden, i.e. the Nordic Prediction method from 1996 (RTN: 96). The advantage with Nord2000 is that you can use specific input data for each bus type, something that is impossible with RTN where in-data for light and heavy vehicles are based on measurements carried out in the early 1990s. Nord2000 has been implemented in different noise calculation software, of which SoundPLAN is the computational tool used in this project. The drawback with SoundPLAN however, is that it is not possible to calculate maximum sound levels with the Nord2000 model as this has not been implemented in the software. For calculations with Nord2000 new input data has been collected based on measurements of gas, electrically charged hybrid buses driving in diesel mode, and electrically charged hybrid buses driving in electric mode on a test track in the autumn of 2016. For diesel buses existing input data for Nord2000 was used based on measurements in real traffic in 2015. The results of these measurements are used not only to do outdoor calculations of bus noise, but also for calculations of indoor noise.

Another disadvantage of Nord2000 is that the calculations are more time consuming, which meant that we had to limit the geographic calculation area to 32 km² in central Gothenburg. It is the most densely populated area in Gothenburg is where the bus traffic is most intense. In this area, bus traffic along with car traffic and other heavy vehicles was calculated within 100 meters from the road center, as well as within 30 meters of all bus stops to see the effect of starting and stopping on noise levels.We have also calculated a small residential area in the center of town where buses dominate namely the area around Bäckegatan, to analyze the impact of bus traffic noise in more detail.

Measurements of the various bus types demonstrates that there are differences between the bus types and that diesel buses cause more noise than the other bus types. A frequency analysis of the sound also shows that the sound from diesel buses contains much more low frequency sound than electric buses. Gas and hybrid buses lie somewhere in between when it comes to the content of low-frequency sound.

The estimates of the health effects and economic costs of bus noise show that diesel buses cause the highest costs of the various bus types included. But despite electric buses being perceived as much quieter it is in general difficult to show any significant difference between the bus types, even if hybrid buses in diesel mode and gas-powered buses contain more low frequency sound than electric buses. There is however a greater difference between bus types at bus stops because diesel, hybrid bus in diesel mode and gas-powered buses make a lot more noise than electric buses during acceleration. When the buses are calculated together with other road traffic, the other road traffic tends to dominate due to the fact that the volume of other traffic tends to be much greater than the volume of buses.

However if you only have bus services near homes (without other traffic), the differences in exposure, especially from 55 dBA and above, is large between bus types and the electric bus is by far the quietest option. For exposure at night, calculated both with buses only and with buses and other traffic included, the differences in exposure to sound levels that can cause sleep disturbances are greater between bus types, and electric bus clearly contribute least to increased sleep disturbance.

Research shows that the link between annoyance to and loudness of noise from heavy traffic, measured or calculated as a daily equivalent noise level in decibel A, is not particularly good. Low-frequency sounds are perceived as more disturbing and are perceived as louder than sound sources that are dominated by sounds in the higher frequencies, such as car traffic. The methods for quantifying the health impact and economic costs of traffic noise need to be developed or supplemented by other methods which more accurately include annoyance and sleep disturbance from heavy traffic in order to be able to make more accurate cost-benefit calculations.

The Nordic prediction model from 1996 is still used for road traffic noise predictions and noise mapping purposes in many cases in Sweden. The model is restricted to A-weighted levels and the vehicle categories only take light and heavy vehicles into account. Weather conditions and ground effects are simplified. The subsequent Nord2000Road model can be used for noise predictions in more complex situations. Nord2000Road uses third octave bands, an advanced outdoor propagation model and more categories for vehicles and ground. Recently the CNOSSOS-EU model has been developed in Europe and can be used for noise mapping purposes according to the European Noise Directive in the future. CNOSSOS-EU uses octave bands and similar vehicle categories as Nord2000Road. The source model as well as the propagation model differs from Nord2000Road. In 2015, a measurement campaign of noise emission in real traffic was conducted in Sweden. This paper presents updated input data for the Nord2000Road source model as well as national Swedish correction terms for rolling noise in the CNOSSOS-EU model to better represent the recent measurement results.

Today's models for road traffic noise are based on the Nordic prediction model from 1996. Since then, several projects have been carried out to develop prediction models, both in Scandinavia and in Europe. In other Nordic countries for example the calculation model Nord2000 Road is used and within Europe the model CNOSSOS-EU will be used for noise mapping. Nord2000 Road has the advantage that the model has a broader scope and can provide more detailed results compared with 1996 model, and there is a willingness to move to that model in Sweden. The model gives slightly higher estimated levels compared to the old model. Input data for the prediction model Nord2000 Road are based on measurements carried out in the Nordic countries and the latest measurements in Sweden are 10 years old. In 2015 new measurements of noise emissions from vehicles in real traffic on Swedish roads were carried out. The results show that the source data to Nord2000 Road needs to be updated to represent current Swedish conditions. The results indicate that Nord2000 Road overestimate levels and suggested adjusted input data are presented. Spectrum adaptation to Swedish conditions are revised. The measurements confirm, however, speed coefficients for Swedish conditions.

Spectrum adaptation terms for other road surfaces than SMA 0/16 (stone mastic asphalt with 16 mm maximum aggregate size, ABS 0/16), which is the most common pavement for high traffic roads in Sweden require more extensive measurement data, but some data for a Swedish drainage asphalt road surface are presented in the report.

Updated input is proposed for Category 1, 2 and 3 for Nord2000 Road. For motorcycles input data can be based on data from previous Harmonoise- and Imagine projects, even if they are designed for Southern European conditions. Some data from the measurement series 2015 are presented in the report, but additional measurements needed when the spread in the results are great. Also for vehicles with alternative powertrains such as electric or hybrid vehicles sufficient information is lacking today to determine reliable input data for the prediction models for Swedish conditions.

CNOSSOS-EU underestimates clearly the emission levels for Swedish conditions, and also have different speed-dependency, so a speed-dependent correction is proposed in the report. Maximum levels are proposed to be calculated in basically the same way in CNOSSOS-EU as is made in Nord2000 Road.

To calculate the traffic noise at different driving conditions such as in urban areas with accelerations or decelerations associated with intersections or roundabouts it is proposed that the methods of CNOSSOS-EU and Nord2000 Road for heavy vehicles (category 2 and 3) is applied. CNOSSOS-EU gives corrections for the total sound power depending on distance from the crossing or roundabout, while Nord2000 Road gives a general increase of the rolling noise with 3 dB for heavy vehicles in urban traffic.

The Nord2000 Road source model allows for separation of rolling and propulsion noise from measurements in real traffic. For the CNOSSOS-EU model this is more difficult because of the co-localization of the two model sources. Separation of rolling and propulsion noise could be beneficial for separation of tire/road noise and vehicle noise for evaluation of the tire noise and vehicle noise regulations.

Denna rapport ger anvisningar om hur ljudnivåer kan mätas på ett standardiserat sätt i byggnader för att kunna jämföras med regler i exempelvis föreskrifter, allmänna råd eller standarder.Folkhälsomyndigheten ger ut allmänna råd om buller inomhus med riktvärden för ekvivalenta och maximala ljudnivåer. Råden innehåller även specifika riktvärden för lågfrekvent buller i tredjedelsoktavbanden 31,5 – 200 Hz. Boverkets byggregler BBR innehåller föreskrifter om bullerskydd i bostäder och verksamhetslokaler, med allmänna råd om högsta tillåtna ljudnivåer. De svenska standarderna för ljudklassning av byggnader (SS 25267 och SS 25268) kan användas av byggherrar för att ställa högre krav på byggnadsverk, t.ex. ljudklass B.Som utgångspunkt för översiktliga mätningar har den internationella standarden SS-EN ISO 10052 använts som referens, med tillägg och anvisningar för tillämpning enligt Folkhälsomyndighetens och Boverkets allmänna råd. Vid mer detaljerade mätningar kan i stället standarden SS-EN ISO 16032 tillämpas, med vissa anpassningar. Mätanvisningarna i rapporten är uppdelade i två relativt självständiga delar, en för varje metod.Denna SP Rapport 2015:02 ersätter den tidigare mätmetoden SP INFO 1996:17, Vägledning för mätning av ljudnivå vid låga frekvenser – fältprovning. Rapporten bygger på de resultat som framkommit från de senaste årens forsknings- och standardiseringsarbete både nationellt och internationellt, samt praktiska erfarenheter av fältmätningar.Anvisningarna i denna rapport har inte samma struktur som en vedertagen standard. Detta för att fokusera på användarvänlighet. Beteckningarna som används är de samma som Folkhälsomyndigheten använder i sina råd för att göra tillämpningen av metoderna så enkel som möjligt. Det kan därför förekomma skillnader mellan de beteckningar som används i denna rapport jämfört med beteckningar i standarder eller allmänna råd från andra myndigheter.Rapporten har författats av Krister Larsson vid SP tillsammans med Christian Simmons vid Simmons akustik & utveckling AB. Även Bo Gärdhagen och Andreas Gustafson vid Gärdhagen Akustik AB har varit behjälpliga under projektets gång. Rapporten har skrivits med finansiering från Folkhälsomyndigheten (tidigare Socialstyrelsen), projektnummer 3P08456 samt 4P08015.

When dealing with urban noise, most of the attention is focused on the typical sources, the ones given by the Environmental Noise Directive 2002/49/EC: major roads, railways, airports and industries. But what happens in protected and quiet areas, like courtyards or parks? They are partly shielded from the previously mentioned sources, but many others might be relevant: maintenance and repair work, glass recycling, loud music, car parking, ventilation and cooling systems, etc. The Sonorus project considers every aspect of the urban sound environment in its holistic approach to the matter. Hence, if non-traffic sources play an important role in quiet areas, they should be analyzed and characterized, in order to evaluate how such sources will affect the environment. This paper presents the outcome of the first stage of one of the research projects within Sonorus, the characterization and synthesis of a fan sound for auralization purposes. The technique used is based on spectral modelling synthesis. The input parameters to the model can be varied in order to simulate various running conditions, such as variable fan speed. The source synthesis is combined with a propagation model in order to complete the auralization process.