Article in ‘Acoustics’

Simulations and Subjective Rating of Acoustic Conditions in a Symphony Orchestra—A Case Study

Acoustic conditions in a symphony orchestra on a concert hall stage are very different from those on an empty stage.
Since inter-orchestral sound transmission and other acoustic conditions with the orchestra present is easier to simulate than to measure, a method for simulations in Odeon models of orchestras in different rooms was developed by this author. This method was applied in the Grieghallen Renewal Project, which involved changes in concert hall, orchestra pit, and rehearsal hall. The resident orchestra members gave their overall rating of playing conditions in the home venues in addition to a number of international venues. Acoustical conditions in the rated venues were simulated and compared with ratings. Several metrics were investigated, and their correlation with subjective ratings varied between r2 = 0.09 and r2 = 0.85. It turned out the orchestra clearly preferred to play in conditions where the direct component and the reverberant component of the inter-orchestral sound-transmission on average were equally strong; |D-R| = 0. Any deviation from equality was associated with reduced preference, with correlation coefficient r = −0.92. Several interesting implications and interpretations of the result are discussed in the paper.

The entire article can be read here.


Management change

Ingjerd Aaraas has been in charge of Brekke & Strand Akustikk AS for 18 years and now it seems natural to search for a new leader.

Together with Ingjerd, the board will lay out a good plan for the management change and clarify the role she will have in the company in the future.
We agree that Ingjerd stays as CEO until summer, says chairman Geir M. Aarstad.

In Ingjerd’s 18 years as a leader, the company has had a very strong development:

  • The number of employees has increased from 19 to 94
  • Turnover has gone from 20 to 130 million NOK
  • All years have produced positive results for both the company and the owners
  • Carried out many large prestige projects in the field of acoustics

From a small office in Oslo, the company has developed into one of the leading specialist companies in acoustics, noise and vibration in Scandinavia. We currently have offices in Trondheim, Bergen, Stavanger, Kristiansand, Oslo, Gothenburg and Stockholm.

The board would like to thank Ingjerd for the great job she does for the company.

Contact for further information:

Geir M. Aarstad, 934 38 803,

Ingjerd Aaraas, 913 76 849,


We open offices in Stockholm!


Brekke & Strand Akustikk expands its operations in Sweden and opens office in Stockholm.

We are proud to have Johanna Carpelan join us as head of our new office in Stockholm. She is perfect for that role, with plenty of experience both as an acoustic consultant and manager.
– We celebrate 5 years in Gothenburg this autumn and the Stockholm expansion will be the next milestone in Brekke & Strands Swedish operations. Our premises are very centrally located in Stockholm and we have plenty of room for talented acoustic consultants who wants to join us, says Ingjerd Aaraas, CEO.
In the Stockholm region there is a strong development in the construction market and we naturally want to participate in this, but as with all our offices, we offer services in building acoustics, infrastructure and industrial acoustics.
Brekke & Strand Akustikk’s wholly owned subsidiary Brekke & Strand Akustik AB is led by Jimmy Diamandopoulos.
– We are pleased that Brekke & Strand is growing in Sweden. It is very important for us to have an office in Stockholm with talented employees who can respond to the market demand for our services, says Diamandopoulos.

Brekke & Strand merges with SINUS AS this fall and will by far be the largest acoustic consultancy environment in Norway. Brekke & Strand (in Norway and Sweden) has a total of around 90 employees after the merger and the annual turnover will amount to approx.130 MNOK.

Merger of SINUS AS and Brekke & Strand Akustikk AS

Brekke & Strand Akustikk AS is currently the largest specialized company within acoustic consulting in the Nordic region. SINUS AS started in 1992 and hold currently 18 employees at their two offices in Stavanger and Kristiansand:
The merger plan has now been approved in both companies and SINUS AS will be merged with Brekke & Strand Akustikk AS during the autumn of 2018.

-We’ll have a unique opportunity to develop our acoustics-, noise- and vibration-services with new employees, new markets and new knowledge. Especially interesting for us is the oil and gas sector. There are a lot of specialized tasks for noise engineers in this sector, says Ingjerd Aaraas, CEO at Brekke & Strand.
– We are two employee-owned companies, additionally the founders of both firms were colleagues in the 80’s, maybe it was written in the stars, Ingjerd says.
-This is a new and important step in a long and productive development for SINUS, says Tønnes Ognedal. He has been head of the company since its start in 1992. -For several years we have been involved in lots of interesting projects for our engaged associates. Our employees are looking forward to even more fun at work through merging with Brekke & Strand! We will continue to take care of our loyal clients. In the merged company we can offer more specialized competence and increased capacity.

After the merge Brekke & Strand Akustikk AS will be a company with 86 employees with offices in Gothenburg, Trondheim, Stavanger, Kristiansand, Bergen and Oslo.

Nordic Sound Symposium 50 years

Nordic Sound Symposium 2018 will take place 31st of mai – 3rd of june

Nordic Sound Symposium celebrates its 50 years anniversary in 2018 as the inaugural symposium was held in 1968. The technical developments over this period has been staggering. At this year’s Symposium we will look forward focusing on the technical developments we see coming towards us in the years to come. Celebrating the 50th anniversary of the Nordic Sound Symposium, we aim to give you valuable input on new audio developments building your competencies for the future.

Website with registration


Event on Facebook



This year’s Master’s thesis in acoustics

The expert group in acoustics in RIF (Advisory Engineers’ Association), has this year as last year handed out the award for the year’s best master’s thesis in acoustics.
The prize of 10,000 NOK was awarded to Paula Cruz Gonzalez for her task of comparing measurements and calculations of sound propagation.
“We congratulate Paula with a well-deserved prize and hope that more NTNU students get their eyes on acoustics,” says Brekke & Strand’s own Tore Moen, who is the head of the RIF Expert Group.

Picture and article on


Weighing off “Osebergskipet”

When the new museum is completed on Bygdøy, the ships will be moved and preparations for this are under way.
New support structures for the ships will also be installed when they are in a new museum. As part of the preparations, load cells are now installed under all supports and arrangements on the Oseberg ship. One will then get the exact weight of the ship and weight distribution.
Load cells are mounted under today’s support and then the ship and today’s supporters lifted a little to accommodate. The first step is to see how the Oseberg ship relies on being lifted up a bit. 4 supports were lifted 2 – 3 mm while it was carefully recorded how the ship responded to this. The first step in the weighing process is done. The ship will be on load cells for at least one year, and it will be monitored how the load depends on moisture and temperature. Meanwhile, deformations of the polls and other critical places are measured.

Christmas presents for charitable purposes

Brekke & Strand Akustikk AS and AB have chosen to donate money for charitable purposes this year, rather than giving Christmas gifts to their employees.

All our colleagues suggested an organization they wanted to support and this year the choice fell on the Children’s Cancer Association (Barnekreftforeningen) and the Children’s Cancer Foundation (Barncancerfonden) in Norway and Sweden.

Hopefully we will make this a tradition in the coming years.




Brekke&Strand is Great Place to Work® certified

Great Place to Work® is a global consultant and analysis institute with over 25 years of experience in measuring and developing trust-based culture and leadership at workplaces. Great Place to Work and their awards for Best Workplaces are assigned to organizations that have proven to have created a good workplace for their employees.

Brekke & Strand Akustikk AS has achieved this certification this year.

The GPTW certification is a confirmation that what we in Brekke & Strand believe in and work for, works. Brekke & Strand is ‘Great Place to Work’ for almost 70 competent and committed employees.

Acoustics in practice

The European Acoustic Organization EEA publishes a magazine called “Acoustics in Practice”.
In the last issue, an article by our own Sigmund Olafsen (and others) has been published. The article deals with the tram measurements we have done for Oslo Sporveier.
Atle Stensland and Tore Killengreen are co-authors.

The whole article can be read here: Acoustics in Practice – october 2017