The goal of this tutotial is to provide an overview of the concepts and capabilities of SoundPLAN.
The standard case of noise control for a community is discussed.
Special considerations like those for industrial noise control are largely omitted. 

To simulate the noise from any source, first the source needs to be analyzed and then the noise propagation must be considered. The noise source is not always a steady signal. In this train example, the noise increases as the train approaches. As the train passes by, the noise is steady, and when the train leaves the area, the source fades again. 

To find the maximum noise level from a single train, SoundPLAN divides the train passage into time slices of 0.05 seconds, calculates the position and speed for the train, and determines the emission per meter of train. For each meter of train, the sound power emitted by the train is subjected to the propagation losses (spreading, air absorption, ground effect, screening, reflection..) to determine the sound pressure. The sum of all sections yields the sound pressure for the various positions of the train. 

With the train speeding along the  track, SoundPLAN simulates 20 positions of the train engine per second. This provides an almost constant time signal for the noise the train emits.

The simulated time histogram can be used to find the absolute maximum of the noise level or, if arranged in a different way, the data will become feedstock for a noise mapping procedure which will generate a real time noise map from a moving train. (The CD has an example).

The Leq from the time series is found by dividing the duration of the trains passage into "constant" noise levels, adding the levels energetically and subtracting 10*log(number of divisions) from the result. The value is the energetic average of the time period of the train passage. As the Leq noise levels are referenced for a specific time period, the adjustment between the train passage and the time period needs to be subtracted. (10*log(Tpassage/Ttimeslot))

For a noise evaluation, the fluctuation of the instant noise level is not significant. In most cases the noise rating is done on the basis of a day time noise level (16 hours) and a night time noise level (8 hours). Some regulations use the maximum noise level and some rate the noise by the loudest full or half hour at night time.

In SoundPLAN, the traffic related sources are described by entering the source strength of a single vehicle or train and then adjusting the levels for the number of vehicles for the time slots day and night. Simulations of the maximum noise level always assume a single vehicle is causing the noise. Superpositions and Gaussian distributions are not possible at present.

The industry noise description starts with the average maximum noise emission and allows the user to define a table with adjustment factors for all 24 hours of the day.

SoundPLAN Noise Assessment

Taking the sources sound power and applying the physical equations of the propagation is only the first step in the noise assessment of the situation. National laws regulate how the assessment or rating is carried out. The descriptors may vary between Leq for day and night, the L10 or the Lmax fast or for the loudest hour. The noise limits for each of the ways to rate the noise situation will probably vary with the area usage. Residential and hospital areas have different needs than and industrial site.

As SoundPLAN cannot foresee every possible noise assessment procedure, the program needs to be able to be customized to the way the legal procedures for the country demand. In the library (see screen shot) the assessment procedure is customized and connected to a matrix of noise limits.

Before we can evaluate the noise,

must be taken.

Without setting objectives and priorities any project would go astray and only waste money, It is mandatory to first set the goals of the project and find out how big the study area is and what data need to be acquired.

Any simulation starts with abstracting the real world into a manageable mathematical model. SoundPLAN requires information about the sources, the landscape over which the noise is propagating and the location of the receivers. The sources are characterized by the source spectra, directivities and times of operation. The geometry needs to be installed in the Geo-Database as a 3 dimensional model of the world with all objects in place that influence the propagation of the noise. Buildings, noise protection walls, elevation lines, hard and soft ground all influence the reception of the noise at the receiver.

The input of receivers can vary greatly depending on what type of results are desired. Single point receivers, facade noise maps and grid noise maps all have their own input requirements the input of all type is guided by the Geo-database.

The second step of a noise simulation takes the geometry from the Geo-database together with the source definition and calculates the noise levels for the receivers. Each receiver is calculated separately; for each receiver, each source or part of the source is calculated independently.

The results from of the calculations are written into specialized files so that the documentation and graphics programs can be supplied with the information needed.

The commands invoking the calculation are written into "Batch" type run files. Calculations of variants can be repeated quickly with new data. Parameters influencing the calculation can be modified easily and the calculation repeated.

A log file keeps track of all parameters, settings and actions of the calculation core.

Table oriented results are written into the documentation part of the program. From the same data generated in a calculation program, different types of tables can be generated. Each table can be customized to the users needs, contents can be selected or deactivated, the layout can be adjusted flexibly.

There are 2 different types of results:

Single calculation results feature intermediate and final results of a single calculation with the possibility of diagrams explaining the hours of operation, frequencies and receiver directivities.

The Expert Table enables the comparison of multiple calculations. Differences between 2 calculations are mapped.

A graphical representation of the results in the form of Grid Noise Maps and Facade Noise Maps presents the "dry" figures of the tables in a visual form.

The main objective in noise simulations is to check if the facility is in compliance with the regulations, and if the noise limits are violated, to find solutions for the problem. Each excess of noise limits is viewed as a conflict. Conflicts can be presented in table form in the documentation or as a graphic. In the graphic, the noise levels are not mapped in accordance with a fixed scale but in accordance to their excess of the set noise limits.

The greater the excess of the noise limits, the bigger the conflict.

When a scenario was simulated and the noise level exceeded the noise limits, a conflict was found. The objective of noise control studies is to find solutions for the problem.

For industrial noise problems, corrections at the source are the most likely attempt. For traffic noise problems, the source modification is limited to changes of permissible speed and the road surface. Therefore the standard solution is to build noise protection walls.

If "active" measures are insufficient, "passive" measures like noise control windows are suggested.

The next part of the Tutorial takes you step by step through the program the way a project would be done. The icons on the left of the following picture are the access buttons to various parts of SoundPLAN.

The Geo Database manages the geometric description and the attributes of the objects relevant to a noise propagation calculation. Data input and further manipulation of the data is a very important feature. Data entry can be accomplished via the DXF interface or digitized on a scanned in bitmap or entered directly with a digitizing tablet.

Data entry is object dependant. Select the object type first and then enter attributes and coordinates for the objects. Definition boxes for the objects are object and standard specific and they open automatically.

Objects can be visible on the screen or hidden according to the selection in the View setting. Aside from the top view, projections to the bottom and the right side are also possible. Create parallel objects and filter out coordinates with the Geo Tools.

DXF

After entering the DXF file-name, the data are imported into temporary Geo-Files. Each layer is stored in a temp. object of it’s own. With the view commands you can select to see only one object at a time and further assign attributes to this object.

If the coordinate system of the DXF file is not identical to the world coordinate system used in your project, you can enter multiple reference points to fit the coordinates.

Bitmaps

Digitizing on screen can be done on the basis of Windows BMP files, which you can get from a scanner or from a map agency. After loading the file, SoundPLAN lets you enter multiple reference points to calibrate the map to your world coordinate system. Stretches in X and Y as well as rotation are taken care of with the Helmert transformation used in surveying. Whenever you click on a point of the map a little enlargement will appear showing you the area where you just clicked.

Digitizing Tablet

Digitizing off a digitizing tablet requires that the digitizer is configured for windows by having a "WINTAB" compatible device driver installed.

For each digitized map, reference coordinates are needed just as for the DXF import or the bitmap. After the transformation is installed, transfer the coordinates with the digitizer send button. When you are outside the map area, the digitizer automatically becomes a mouse.

Object Type

In order to enter the attributes specific to an object, you must first select the object type. This selection can be done by choosing one of the entries in the object combo box or by clicking the appropriate icon. In the options menu, configure the screen layout to your desire by having all object icons in one bar or by grouping them according to their function. The object icon bar can even be detached or docked to the right side of the screen.

View

You can select which data is visible by defining the criteria. If "All Objects" is activated, you will see all the loaded data. If "Current Geo File" is selected, only data in the active Geo-File is shown. "Current object type" enables you to limit the output of the data to the single object shown in the combo box on the right. "Undefined objects" enables you to see imported objects that should have been associated with attributes but have not received any yet. (A dxf imported road needs to be assigned an object type and needs to have attributes). If coordinates in an area are marked, all marked objects can be presented with the option "show marked objects."

Projections

View options are the top view, or the projection of all elevations to the bottom window or to a window on the right side of the screen. Data marked in one screen is automatically marked in the other screen. This helps you control the consistency of your data.

Geo Tools

Geo Tools are used to manipulate the geometry. After marking an object, certain tools are available to further process the data. Tools that do not apply are grayed out. There are polyline tools and general tools. The polyline tools filter the data, calculate right angles and interpolate intermediate coordinates in a string. Right angles are used for buildings after digitizing. The filter is used for elevation lines to decrease the amount of data within the project. General tools include generating parallel lines, connecting interrupted polylines, and fitting data by rotating and scaling.

SoundPLAN has different source types for point, line and area sources. 

Point sources are only used for industrial sources, the spreading is 6 dB per doubling of the distance.

Line sources are used in the industrial sources as pipelines, conveyors etc and as roads and railway lines. The spreading is 3 dB per doubling of the distance.

Area sources are extensively used in the industrial models and as parking lots. The spreading is between 3 and 6 dB depensing on the distance to the source.

For industrial noise sources, the first coordinate of the source opens a table for defining the source attributes. This is where you define the acoustical properties of the source (frequencies, time histograms) and where you can further define the geometry. The spectra etc. are linked to the library where the information is stored for all projects.

No noise source emits the same amount of noise in every direction. To account for this unevenness, sources are associated with directivities. For some types of sources (trains) the directivity is a fixed part of the calculation formulas. For other sources the data must be entered.

The directivity must be entered so that the overall sound power does not increase or decrease because of the directivity. The diagram must be normalized. The library makes special provisions for this case.

SoundPLAN supports 3 types of directivity: plain horizontal directivity, rotational symmetry around a vertical axis and the full 3D directivity where each frequency can have it’s own directivity. In the library, the directivity is associated with the type of directivity. The actual orientation of the source is set in the Geo-Database.

The most important characteristic of a noise source is the sound power given in spectral form. The source can be associated with a discrete mean frequency (most often used when no detailed information is available) or it can be defined via a third octave or octave band.

Data in the library can be entered as it is available to the user, it can be typed as linear data or filtered in accordance to the A..D frequency filter. In the calculations, all data is used in its A filtered variant, and for the output it can again be run through the filter curve to represent the linear, A..D filter.

Air absorption, screening and ground effect are frequency dependant. The formulas, however, depend on the calculation standard used.

The SoundPLAN Library has provisions to manage an extensive stock of source data. Search functions allow for a structured keyword type hierarchical storage of the data. Each noise source can be associated either with mean frequency sound power or an octave or third octave spectrum. For the spectral representation the minimum and maximum frequencies are user defined. Data can be entered as linear spectra or filtered as dB(A)..dB(D). All source characteristics (groups, characteristics, directivity, spectra..) are stored under the name of teh source in either a local or global library.

The sound power of a source is seldom constant over the 24 hours of a day. Depending on which type of noise assessment is used, SoundPLAN needs the averaged data over the 24 hours of the day or the noise values for specific hours.

For transportation noise, the source is usually not described in terms of sound power but rather as a sound pressure with a set reference distance from the source. (For details of the standards, see the annex in the handbook). The models are set up with a given sound pressure level for a single vehicle at a reference speed. The number of vehicles, corrections for heavy vehicles, speed, inclines and road surface are add-ons to the basic noise level.

For train noise, the noise value is usually given as a noise level per meter of train length. Thus the train lengths times the train numbers are a measure for the noise the train generates. Although train noise is not omnidirectional, the directivity of the trains is figured into the formulas and the user does not have to consider it as an extra adjustment.

For train noise the data needed are the number of trains, type of train, length of train engine type speed of train and factors depending on the standard used (ballast bed, tight radius, bridges). For all trains on the line the comprehensive Leqs for desired time periods are calculated.

For road noise data entry is needed on the number of light and heavy vehivles in a time period, the speed, type of road surface, gradient. 

Noise emitted from the source may encounter obstacles on the way to the receiver. The obstacle definition can vary. In SoundPLAN, noise protection walls and buildings can reflect noise. A reflection is only permitted when the angle of incident equals the angle of excitant. Both the site plan and the 3rd dimension are checked in the calculation.

A reflecting object can be either a noise protection wall or a building. For a building, the energy loss in the reflection is described as a loss of x dB in the reflection. As a noise protection wall has two sides, the front and the back of the wall may be reflective with either the same reflective properties or individual reflection losses.

Objects in the transmission path cause screening losses. In SoundPLAN many different objects can be obstacles in the path. Each object has slightly different screening functions:

Elevation lines only act as screens when they intercept the line of sight.

Break lines describe a vertical drop in the landscape and contain two elevations. From the higher side, the sound wave sees it as an elevation line. From the lower side it is viewed as a wall.

Noise protection walls diffract and reflect noise.

Walls or earth berms only act as shields.

Buildings diffract the noise over them.

Depending on the applied standard, the screening effect over the object is used or the screening around the left and the right side.

Ground Effect

Sound waves traveling over a plane interact with the ground. The mechanisms are too complicated to describe in this tutorial, plus each calculation standard assess this effect differently. Some of the standards calculate the ground reflections (Nordic road, Nordic industry, ÖAL 38, Iso 9613), but most of the standards assess the ground effect from the average height of the line of sight above the ground.

The interaction between ground effect and screening is very complex and is part of the description of the calculation standards in the annex of the handbook.

Air Absorption

Air absorption depends on temperature, moisture and pressure. SoundPLAN offers multiple standards to calculate this parameter (ISO 9613/1; ISO 3891; ANSI 126).

Atmospheric conditions greatly influence the sound propagation. Wind and temperature can "bend" the rays up and down. With upward refraction, shadow zones occur close to the source, but they are very quiet. Turbulent effects further complicate the situations.

Each of the calculation standards handles the questions of meteorology differently. Most methods ignore the variations in the meteorology and pick either the most likely scenario or model an average downwind situation. Only CONCAWE, ISO 9613 and Gaussbeam allow the user to control the meteorological conditions. Click on the standards to get specific information.

SoundPLAN applies different types of receivers. Single point receivers are used to generate detailed information about the interaction between stand alone receivers and their sources. Most of the results will be processed further in the Documentation module.

Facade Noise Map, Grid Noise Map and Cross Sectional Grid Map are maps having many individually calculated receivers. The Facade Noise Map calculates a string of receivers along the facades of buildings. Height and spacing of the calculations are user controlled.

Grid Noise Maps calculate a triangulated mesh of the geometry and place receivers in a set spacing above it. In the graphics module, the discrete points of the Grid Noise Map are converted into solid contour maps.

Two components are needed for sources, receivers and all objects placed in the transmission path. Three dimensional coordinates define the geometric location, and attributes further describe the object’s properties.

The coordinates can be digitized (see Geo-Database section) from a plan placed on a digitizing tablet or they can be digitized on screen on an imported bitmap. The best way, however, is to reuse an existing coordinate base generated in other programs. When data are read into the Geo-Database they must be 3 dimensional coordinates or it takes too long to find the elevations in a plan. Data from CAD programs should be organized in layers with a description of each layer. In the Geo-Database, the data can be viewed layer by layer and be converted into the appropriate SoundPLAN object.

To generate the properties of each SoundPLAN object, dedicated data entry boxes are opened automatically after the first coordinate of an object is entered. Numerous boxes are adapted to the calculation standard. All parameters are explained. The object’s properties can only be entered via the keyboard.

After an object is entered, clicking the left mouse button on an object will reopen the data entry box.

The project Noise control for a residential contains the following Geo-files: A: All basic geometry with eleva- tion lines, residential buildings and existing roads. B: Planned quarry with all sources and elevation lines C: Industrial buildings shielding the residential D: Noise protection wall E: Modified noise control wall From the established building blocks the situations show permutations of the different sources and geometry. Situation 1: Status quo without the quarry Situation 2: Situation with the quarry in place without any noise control Situation 3: Plan with the quarry and industrial buildings provid ing shielding to the residen- tial sites. Situation 4: Noise control only with bar- rier Situation 5: Plan 3 with and additional noise control wall Situation 6: Plan 3 with modified noise control wall

SoundPLAN calculations are organized in a program of their own so that calculations can be run in the background while other data is prepared in the Geo-Database. The calculations can be chained together in a table form so that multiple calculations can be processed one after the other.

The tables of complete calculation runs are contained in "run" files. Here you define all parameters needed for the calculations. The program requests only the parameters needed for the specific calculation. Most parameters are already preset with sensible values. Some of the settings are from the standards project setup menu of the SoundPLAN manager and can be customized for the local calculation run.

A log book keeps track of all events like warning and error messages during the calculation.

Every noise map consists of single, separately calculated receivers. Every receiver calculates the noise from multiple sources. For every source, SoundPLAN evaluates the parameters listed below to calculate the sound pressure contributions at the receiver.

SoundPLAN is a standards based program. After selecting in the SoundPLAN manager which standard shall be used in the calculations, all data entry in the Geo-Database is geared for that standard. The calculation core uses the prepared data, loads it into optimized structures into memory and processes the data in accordance to the selected standard.

In SoundPLAN all standards of a noise type included in the license are available without additional cost!

At the moment many European nations have implemented their own methods to calculate and evaluate environmental noise. The European Community has started work on a set of common European regulations to replace the national laws.

As soon as the formulas are available, SoundPLAN will implement them as additional standards.

After opening the RUN file, choosing the calculation type, selecting the standards and declaring the calculation parameters, you can start the calculation Batch. The required parameters and the format of the output change slightly for each of the calculation types.

The calculation core has three parts:

The RUN File declares all parameters for the calculations. Local declarations modifying a global default type setup minimize the amount of setup work needed.

The Graphics show the data selected for a particular run in a graphical form.

The Log-Book notes all actions occurring in the calculation core and writes a log of the warning and error messages.

SoundPLAN scans the geometry angle by angle looking for sources. The user sets the scanning angle. For accurate results the angle should be between 0.5 and 5 degrees. For line type source geometry, intersections on the median of the search triangle are calculated with all geometry present in the calculation. All objects intersected between the source and the receiver are chained together in an object string. The spreading is calculated from the distance between source and receiver. The calculation of the ground effect evaluates the ground type and shape as well as the distance. Screening and reflection depend on the objects found between source and receiver.

When a reflecting object is found in the direction of a search ray, SoundPLAN evaluates the distance criteria for the existence of the reflection, finds the mirror receiver and searches from the mirror receiver through the reflection point into the new direction. Any source found in the new direction is evaluated the same way as for free field conditions. To account for the reflection losses, the part of the energy absorbed by the reflector is considered. In most cases SoundPLAN reduces the level by the linear reflection loss. However, for frequency dependant industry noise, full absorption spectra can be calculated.

This picture depicts all possible incoming noise contributions in one start direction. All reflections up to the 3rd order are drawn on this plot.

SoundPLAN has no limit on the number of reflections calculated, but for practical applications the number of reflections should be smaller than 10. All reflections with higher order will not increase the noise level at the receiver any further because the extra distance traveled and the loss of the reflections has already depleted the energy.

For single receiver calculations, the data the calculation core generates is placed into databases for the documentation to be converted into full reports. There are two types of reports available: One shows the intermediate values and final results for a single calculation, and the other compares multiple calculation runs.

The level of material supplied to the documentation is requested in the RUN command. There are check boxes for "Plain Results," "Level Charts," "Detailed Results" and "Calculation Protocols."

The different reports are offered in the documentation. When they are activated, the data is retrieved from the databases and the reports are displayed on screen. Any Windows compatible printer can print the reports.

The result tables are delivered as templates which the user can customize. The sheet layout, header and foot note boxes with bitmap logos, fonts for the headlines and columns, and the individual columns width can be customized using the special layout boxes. Marking the columns in the setup table activates or disables them.

One of the report types available has detailed diagrams for each receiver. The frequency distribution uses red bars for daytime and green bars for nighttime.

Day histograms show variations of the noise load during the day at the receiver. The noise assessment uses the day histogram to generate single descriptor answers such as the NEF, SEL..

Noise level charts show from which direction the noise came and which quantity of noise was received. Yellow rays depict direct input and red rays show reflected noise. The length of the ray indicates the magnitude of the received noise.

SoundPLAN Graphics is a module of it’s own. This allows the graphic functions to be tailored to the layout requirements without overloading the Geo-Database.

The graphics modules use data from the calculation core and raw data from the Geo-Database and present it in the defined space on the drawing sheet. Explanatory text boxes, bitmaps and other features enhance the drawing. The output to the printer is accomplished through the Windows device interface.

One of the graphics modules is the Facade Noise Map. For given buildings, the calculation core calculates receivers equally spaced around the building. The data preparation starts in the Geo-Database with marking the sides of the selected buildings that should be included in this map.

In the calculation, receivers are placed with a definable spacing around the building. For each of the buildings, up to 255 receivers representing up to 255 floors can be placed. The lateral spacing of the receivers is given by the height of the floors assigned to the particular building.

In the graphics, the Facade Noise Map can be drawn for the lowest/highest noise level or for a particular floor. The shape, colors and layout parameters can be controlled in the graphics itself.

Double clicking on the Facade Noise settings in the Object Setup opens the control box with the Facade Noise Map parameters. The symbol for noise values less than the noise limit can be selected separately from the symbol for noise levels exceeding the noise limit.

For black and white display, the noise levels may replace the plot version that works according to a color scale. The text options are available at the bottom of the control box.

Aside from showing noise values, SoundPLAN can also show the requirements for different window classes. If the window classes are set in the color scale to the appropriate intervals and the object setup is switched to intervals, the interval number placed inside the symbol will represent the window class required for the noise load outside the building.

The Grid Noise Map shows the noise levels of an area rather than for single receivers. The map can only be presented for one time slot at a time. At loading time SoundPLAN will ask if the map shall be drawn for daytime or nighttime.

Grid Noise Maps and the contoured variant can be presented in many different ways. The user defines the color scale for the fill colors. Up to 16 colors can be assigned automatically. If the scale should have more colors, the selection can be made color by color.

The map can be represented either as a Grid Map or as a Contour Map with or without contour lines. Middle lines can be activated to mark the middle of each interval.

The calculation grid shown here has every receiver represented as a square with colors from the color scale. The version of the Grid Noise Map represents the raw version of the data.

The scale is automatically generated when the file for the Grid Noise Map is loaded. Clicking the scale box on the screen and selecting "edit content" opens the scale for modifications. Start value, interval size and the color sequence are selectable.

The calculation follows a user defined but constant grid pattern. The distances between receivers in the X-axis and in the Y-axis are constant.

SoundPLAN generates the contour lines through the grid pattern by calculating which grid cells are contained within a certain noise level. The noise values are interpolated between the grid points . With this basic polygon method, the contour lines can be drawn as straight lines. For better viewing, the contour lines are smoothed with a Bezier algorithm. Several parameters allow the user to smooth and straighten the contour lines.

For export purposes the smooth contour lines usually "overload" the target system, so it is preferable to export contour lines only as straight lines.

Normal Grid and Contour Maps depict noise values for an area. As the requirements for noise control vary greatly between areas (i.e. residential versus industrial), a more suitable representation of the noise values is not the absolute scale but the relative scale presenting how much the noise levels in certain areas are exceeded.

In this picture the area definitions are made visible with the hatch pattern and the area symbol. By choosing an area type, the noise limits are also known, so the difference between the noise levels and the noise limits is drawn in the form of a conflict map. A conflict is an excess to the noise limit. The threshold where the violation starts is user defined. Conflicts can be mapped that are still 1 or more dB from the maximum allowed value.

In the SoundPLAN noise assessment library, the user defines the formulas how time variant noise events shall be assessed (NEF, SEL, Leq8h, Leq16h, Lmax...). Penalty times can be defined for each of the areas for one or multiple hours of the day. The noise limits are assigned to the area definition for the time slots the assessment standard requires.

Conflict Maps can be combined with Facade Noise Maps showing details of the noise values.

When noise levels exceed the noise limits, SoundPLAN helps with preparing noise control measures. For traffic noise problems, optimizing noise control walls is a suitable solution. Other tools suggest the type of noise control windows to accomplish a given noise level inside the building. The Filter setting controls the evenness of the contour lines.

Use Wall Design to calculate the optimal noise control wall. The optimal ratio of cost to performance is the aim of this module. The optimization takes multiple receivers into consideration at the same time. The optimization parameter can either be the minimization of the wall dimensions or the minimization of the wall cost.

This page shows a typical diagram for the performance characteristics of a noise control wall. At first the receivers have hardly any benefit from the noise protection wall as the noise is carried over the wall. As soon as the wall reaches the line of sight, the performance is good until the wall reaches the saturation point.

The performance diagram shows the wall has to reach a certain size before it is effective, but it is very uneconomical to continue with the wall past the point of saturation. The filter setting controls the evenness of the contour lines.

This is a typical diagram showing the efficiency of a noise protection wall. The engineers task is to find the point where more wall no longer significantly increases the effects the wall creates.

The user determines how much wall should be calculated.

The performance of the noise control wall can be checked with cross-sectional maps depicting the before and after state and the differences between them.

The requirements of noise control windows depend on the type of room (bedroom, living room, utility), the noise level outside, and the transmission through the walls. The window and wall sizes (given in square meters) and the transmission loss of the wall in dB(A) are used to determine the needed transmission loss of the wall. The magnitude of the loss mandates certain window constructions with single / double / triple- pane, forced ventilation etc...

The calculation of the window requirements is combined with a cost calculation in SoundPLAN.

SoundPLAN is a good help for noise evaluation. For planned industrial sites, the maximum noise emission per square meter is defined and the noise level at critical receivers is checked. The Filter setting controls the evenness of the contour lines.

If the noise at critical receivers is a potential problem for the development, noise limits (noise quotas) should be written into the development plan.