The Hovindammen plateau extends to the motorway and contains playgrounds and sports fields. In this wide-open field, the weather and natural flooring significantly influence how sound propagates and seeps into the residential areas. In particular, temperature gradients above the grass floor covering and wind conditions also affect how people perceive the motorway several hundred meters away. The warmer the ground, the less noise the motorway makes because sound moves away from the ground. When the soil is cooler than the air, the motorway 700 m away can be perceived as noisy and distinctly noticeable and could easily disturb someone who reads a book.
Another critical factor in how you experience the Hovindammen plateau is whether you can hear people playing games, having competitions or doing sports. The more social activities of the neighbouring communities take place on the sports fields, the less the motorway is perceived as disturbing. Peoples’ sounds and voices will help keep your listening attention to the location and drive the motorway noise into the back­ground of your perception. As you go downhill towards the city centre and approach the first buildings, the plateau’s acoustic space begins to fade out, at first almost impercep­tibly and then rather abruptly. When your head is below the plateau level, you immerse yourself into the acoustic space connected with Grenseveien.

Deichmansgate has been redesigned to improve surface water conditions in terms of natural retention and on-site drainage. Pocket parks and plantings help collect the surface run-off rainwater from the building roofs and the street and infiltrate it on site. Permeable cobble­stones replaced the paving of the road to increase the capacity of water drainage. Compared to excessive and expensive water treatment in wastewater infrastructures, rainwater that is locally controlled and treated where it occurs has several benefits for the municipality and the developers. It also has significant spill­overs into urban planning and environmental objectives for urban climate, biodiver­sity, and noise control.
The new design approach for Deichmansgate resulted in a visually as well as acous­tically attractive place. The proportion of more natural and permeable paving is large enough to make an audible difference to the street’s absorption and diffusion. With the cobblestone street and the angular shaped building facades, the combination of materials and surfaces in Deichmansgate creates the right conditions for sound quality. Also, the planers have removed parking spaces from the street and replaced them with seating, designed rainwater features for the younger children. Also, the rainbeds can be maintained and used by the residents. These gestures allow people to better engage with their own home and give it their full listening attention.

Tøyenparken is an important inner-city park next to the botanical garden and the former Munch Museum. It hosts major events such as the Øya Music Festival and borders the inner-city ring road. Due to its central location, the park is not quiet in terms of noise levels. Still, since you can hear from the hillside far into the city, you can identify and track individual sounds from the area as distinct from the general background hum. When the roads are less busy at quieter times, and the sport fields and the pool of Tøyenbadet are closed, you can even hear the tower buildings’ subtle ventilation sounds on Tøyentorg.
In contrast to the flat, wide field of Hovindammen, the terrain in Tøyenparken is shaped almost like a flat, somewhat irregular bowl with some steep edges, resulting in a surprisingly diverse acoustic arena. In some areas of the park, the sounds tend to be focused and amplified, while in other parts, the park’s material conditions tend to disperse the sounds. In addition to the slopes and the absorbent ground materials, the magnificent trees scenically enhance space perception. Especially in fine winter and summer weather, the park is full of people and playing children, creating a wonderful atmosphere for all kinds of people, whether they are relaxing, involving in social activities or playing sports. Then the countless voices and sounds of people make the acoustic space of Tøyenparken reverberate.

A profound transformation is currently taking place between the city centre and Groruddalen, away from a predominantly commercial-industrial history, towards more family-friendly housing developments and new jobs. Tiedemannsparken is one of the early urban planning projects in Hovinbyen, the name of Oslo’s largest development area at the time. The park’s location is close to a newly constructed footpath and cycleway to connect the different areas and ensure excellent accessibility for residents. It allows the place to establish a diverse mixture of sounds from passers-by and residents, from children playing and walkers, mingling with the sounds of the commer­cial activities present.
The relatively large residential units and a former redesigned commercial building, the 12 storeys high Narvesenbygget, surround the park. Standing in front of the residential tower (i.e. at the photographer’s position), you can hear your voice reverberates in the building. The balconies on each storey create a single acoustic reflection of your voice. Together, the 12 individual reflections are strong enough to blend into the city sound and make a distinct perceptible difference. Since each reflection reaches your ears at different times – the lowest balcony row has the earliest echo, the top balcony row the latest – you will not hear a single, rather sharp echo, but a sound with an impulsive fade-in and a more subtle fade-out.

The new footpath and cycle path through Hovinbyen, which currently has no name, leads near its entrance to a square with fitness equipment surrounded by ware­houses, industrial buildings and housing developments. Here the surroundings are surprisingly quiet compared to other sections of the path. Large birch trees and natural ground coverings and surfaces broadly support this perception of tranquillity. However, the place was not frequently used by people while we were investigating it. People seem to pass by and not pause their way.
The sound at this site depends very much on the wind and weather conditions: The place can sometimes sound rather dull, other times all the more lively as the leaves of the birch trees sing in chorus. Although the trees and greenery dominate the place’s scenic perception, sometimes the sound does not have the same appeal. The ventilation machines’ background hum creates a schizophonic situation, a term used to describe when the sonic expectations do not match the visual qualities entirely. A few metres further up, you can even hear the hum of a transformer along the way. Given the rather technical and functional acoustic conditions and the fact that this is a play and fitness area, a careful acoustic design with a subtle sound mixed in between the natural and technical sounds would be desirable to make the place more exciting.

Lille Tøyen Hageby was built in the years after World War 1 according to the garden city principle that was popular at the time – the alternative approach of the industrial city’s dense block development to bring city residents closer to nature and improve their well-being. In contrast to up-and-coming Hovin­byen, where large buildings and warehouses intertwine in transport infrastructures, Lille Tøyen Hageby captures your senses and grabs your attention immediately when visiting.
There are three city squares in the area, dividing the streets and buildings into smaller urban spaces, all of which differ in size and shape and their balance of openness and privacy. In this way, the area has several urban spaces perceived as acous­tically different and yet connected. The place is famous for families, and children often take ownership in acoustic terms with their games and activities.
The rectangle is the main shape, both in the ground plan and in the buildings’ bricks; areas and surfaces are divided into smaller and smaller parts, creating a repetitive yet varied geometry. The uneven, rough and angular surfaces and the differentiated ground plans make sound disperses and spreads out in all possible directions. The natural floor coverings are more sound-absorbent than the building facades and improve the sense of tranquillity in the area.

Sommerfrydhagen, next to busy Tøyentorg, forms a trapezoid-shaped park with a hard surface area for the play­ground and a more natural surfaced rest area of about the same size. The wooden fence at the main street does little to reduce noise here; for one reason, it is far too low and too sound-permeable. For the main reason, street noise reverberates in the buildings and spread quickly into the park. Even with much stronger walls, traffic noise from the main street would be audible and more or less unavoidable. In the garden, some noise also results from the smaller street opposite, which can be even more dominant at times.
The waist-high embankment, the planting of big trees, and the park’s ground design are visually appealing. Still, they cannot provide the necessary conditions to establish a voice for the park. When the garden is empty, people perceive the park as a space surrounded by street noises: All buildings reflect all sounds into the middle of the park. A person who is not that interested in traffic must feel lost here. Surpris­ingly, you will find a quiet street directly in the extension of the park. The buildings’ arrangement forms a street that has the dimension of an inner-city courtyard with a wide and slightly curved body. At one end of the road, two corner buildings and the transverse brick building at its opposite end acoustically enclose the space and provide excellent noise protection from the main street.

Even though walls are nothing unusual in a city, tall buildings can form deep and noisy canyons. In Akebergveien, you will learn that walls differ not only visually but also acoustically. Along one side of the street is a raw concrete wall about two storeys high; along the other side is a row of five storeys tall. The concrete wall shows neither a geometric structure on its surface nor a variation of materials. On the building side, the wall is recognisably more varied and lively. Acoustic traces from the windows, doors and entrances suggest who might live in the buildings and what people do there. Such information from social inter­action is challenging to hear on the concrete wall. Together, both walls act as an amplifier for traffic noise, especially when trucks and buses reverberate in this acoustic channel.
The acoustic situation immediately changes when you turn off from Akebergveien into Klosterenga Park. The buildings and the wall (still the same as above) form an acoustic space experienced as much more open, less repulsive than in the street. Traffic noises are yet reflected on both surfaces and even travel along the wall deep into the park. One can quickly test the echoes’ directions with one’s voice or by clapping one’s hands. However, the green and the more natural terrain take over the listener’s attention, who experiences the park more and more calmly the further he goes into it and gains distance from the street.

Harald Hårdrådes Plass lies in a street where the buildings form a sound channel that is typical for the inner-city area. In most cases, the building blocks’ corners are bevelled or rounded to create a few extra metres of space in the streets. At Harald Hårdrådes Plass, the buildings form a trapezoidal square which is quite large compared to the road. You will experience a noticeable change in how traffic noise, especially from trucks and buses, reverberates through the square. Although less intense and repulsive than on the street, the square’s layout and the buildings ensure that sounds remain trapped. Plantings, ground materials, and even the elevations along the pedestrian walkway are far too weak to compete with the buildings’ acoustic conditions. In this case, the street is elevated and makes traffic noise from higher levels in the street propagate through the channel. Even if these conditions do not seem attractive, there is a real chance to follow better the acoustic argument. The direction of Schweigaardsgata outweighs the acoustic orientation for pedes­trians, which should instead turn towards Klostergata as it is perceived as less noisy. It is current­ly used as a neighbourhood car park. Still, it could better connect its scenic design to Klosterenga Park, including a new and improved underpass of the rail­way line to St. Halvards Gate. Deichmansgata could inspire a design approach.

Minneparken contains ruins and foundation walls of Oslo’s most important buildings and places of worship dating back to the Middle Ages. Olavsklosteret divides the park into two parts, one further from the main streets than the other. Here, the approxi­mately man-high boundary wall and surrounding buildings reflect sound into the park. The natural ground is very sound absorbent; you immediately experience body tension changes when entering the park from Arupsgate, where hard materials and surfaces predominate. The hand-hewn stone’s boundary wall reflects all sounds in the foreground of the park, while the buildings behind the wall define the acoustic back­ground. Thus, at times, y0u can hear the tram reverberating in the building facades.
The ruins and foundation walls give an impression of how reliable, chiselled natural stone walls reflect sound in very irregular directions. Compared to a machine-made wall, which can be very regular over extensive areas, with little variation in shape and no material changes, older walls scatter the reflected sound back in all directions. The rougher the wall is in its material surface, the more cracks and cavities it has, the higher the absorbing part of the sound energy. The medieval wall always echoes and reverberates but shows much more difficulty in amplifying and resonating sounds, which seems more the modern wall’s character.

The open, scenic impression of Middelalderparken makes you gaze out into Bjørvika and its new iconic buildings, including the Munch Museum. There are also ruins from the Middle Ages here, and the water basin still refers to the shoreline of that time. You can hear city sounds from many directions in Middelalderparken due to the flat terrain’s openness, with the main road being the most dominant in the front area. At the same time, the rail­way lines border the park in the back. The main road’s noise predominates and fills the acoustic space, not unlike a fog that a single person might perceive as grey noise. The railway line is acoustically active from time to time when commuter trains pass by almost silently, and the noise of the much heavier goods trains enters the park from behind.
The perception of the constant hum is modulated and interrupted by slender but substantial deciduous trees with mesmerising sounds in the wind. Climatically more stable acous­tic conditions have the old industrial buildings of the railway workshops and the ruins. Near these building surfaces, one’s voices emerge more articulately and clearly than further away. Even more surprising is that the waist- to man-high ruins can divide the acoustic space into smaller parts and make the space in the open environment more private to experience. Such observations will be of inter­est when developing design approaches for the redesign of the railway’s workshops.

Henny Mürers Gang is a passage between two newly constructed buildings near the opera house and connects Operagata with Dronning Eufemias Gate. The path follows a slope, slightly inclined with the boulevard at its upper level and the minor street at its lower level. Due to the sharp corners of the buildings and the slope, less traffic noise spreads into the passage. In the passage, the sound is precisely thrown back and forth between the parallel building facades, extending the time of its decay. The foreground noise predominates in the little triangle square at its lower level, pushing the boulevard out of perception. Unfortunately, the opera house’s ventilation machines fill the square with a rather unpleasant, diffuse noise from one of the triangle sides.
The benches around the waist-high rain bed could invite one to pause in the hum of the city. However, they are too weak to provide an appropriate counterpoint in scale and materials, visually and acoustically. The planting and trees turn out to be almost irrelevant in the context of this large scale and technical type of mate­rials. In particular, the passage’s design approach could have been more focused on its function as a meeting place for people. At busy times when many people meet for lunch or a coffee, the small passage acoustically lights, causing people’s voices to glow in the building facades.

In conjunction with Anne-Cath Vestlys Plass in front of the new Deichman Library, Christian Frederiks Plass defines the public space oriented across the boulevard in the Barcode area. It is a busy square that connects Bjørvika with the city centre area; thousands of pedestrians cross the square every day, giving it its voice. Although the Dronning Eufemia Gate traffic can be massive at times, the spatial dimensions and the number of people are large enough to outweigh the noise. Here, the sound reflects on the large surfaces but can hardly accumulate and amplify between the tall buildings like the boulevard. You can hear the reflections from each façade, but the buildings are too far apart for the reflections to build upon each other. In particular, sounds from buses, trams, and trucks are per­cei­ved as less repulsive because fewer buildings are between to resonate.
Since the front is open to the fjord, this acoustic space audibly connects to the massive one shaped by the fjord. As your gaze wanders to the water, you acoustically experi­ence the vastness of the landscape. The scenic impression will appeal to eye and ear alike and make you curious to follow the space to the fjord. The fountain could mark the entry to the station’s main square and Karl Johans Gate. As the fountain is currently closed, this passage between the fjord and the city centre area is less articulated than it could be.

High buildings surround Youngstorget: at the back, the arcades at Møllergata, from where ramps lead down to Youngs­torget on both sides of the square. The iconic red brick front building houses a theatre, while modern office buildings flank the sides. The dimensions of the square and the buildings’ scale form an acoustic space that people experience as open, reflecting sounds from all city directions into this space. Especially from Møllergata above the arcades, you can hear and follow how the city creates this distinctive acoustic background between the buildings. From this elevated position, you will also hear all the voices of people in the square. The square has a long tradition of serving speakers and market traders. Its central location makes it a natural meeting place between the busy city centre and the popular Grüner­løkka.
Voices and footsteps are thoroughly modulated and activated by the cobblestone floor: each stone is slightly different from the next and reflects all the sounds in a very differentiated way, helping to experience them as softer, more lively than an asphalt floor can. The central fountain creates another sound that will draw your atten­tion to Youngstorget. Thousands of water sounds mingle and captivate the acous­tic space. As the fountain is on several levels, its sounds spread in all intensities and vari­ations, from splashing, flowing, rushing, dripping, and being modulated by wind and weather.

The Vulkan area, a former foundry with mechanical workshops along the river Akers­elva, was transformed a few years ago into a multifunctional urban area with flats, shops and meeting places attracting many people. The entrance from Grünerbroa leads people through a narrow passage to the two triangular main squares of different sizes. The former factories have been carefully preserved, keeping iconic brick buildings of different shapes, geometries, and volumes that help avoid standing waves. The new buildings’ design approach incorporates this diversity with large volumes but differentiated surfaces and heights.
The buildings’ arrangement creates highly asymmetrical public spaces whose dimen­sions could be reminiscent of old town areas. However, the blank concrete floor does not fit this spatial reference. The design of Torggata shows a modern inter­pretation of a cobblestone floor, precisely chiselled stones that have a flat and even surface, gently reflecting and absorbing sound when walking and cycling on them. In comparison, the concrete floor is acoustically indifferent and rather monotonous, leaving it to the walls alone to modulate the sound quality. It seems to work well in the Vulkan area because visitors and residents have their personal sonic variety of voices, footsteps and other sounds. Their reflections float and mesmerise in the faca­des and bricks, creating a social, lively atmosphere that holds the listener’s attention to the place.

This booklet comprises the participants’ feedback and observations on 15 locations along the walking routes. It also includes an urbanist’s observations and descriptions for each place. These listening experiences create a basis for further development of these places. By comparing them to each other, the location’s characteristics and acoustic qualities become more clearly articulated. In particular, the places can be understood as sound reference points that can help designers and planners make sound-aware decisions in their current work. With this in mind, the intentions for integrating the acoustic argument into the design and planning process are as follows:
_ Step 1: Imagine how the acoustic differences and similarities of two or more places could parallel the residents’ acoustic experience.
_ Step 2: Anticipate how a particular location or element such as a building surface, fountain, or street design could complement and connect to Oslo’s ongoing projects.
As architects, plan­ners, builders and other actors involved in the urban planning and design pro­cess follow these steps on a walk, they will become connected with their environments in new ways. They will begin to gain more of a personal, social point of reference for the sound of public spaces. The Oslo Sound Reference Points possess great potential to support these objectives moving forward.