Acoustics in sports halls is quite a hot topic in Holland. As you probably have seen before on AB it even was an issue on national TV. In his daily work Guus Klamerek, Concept Developer Education, meets a lot of acousticians who are dealing with this matter. He learned that they are doing their own small studies and use their own way of calculating. Since you have high parallel walls, hard surfaces, a non diffuse sound field and high ceilings. Next to that you have different users, different sports, people moving around all the time etc. These sports hall complexities led Ecophon Holland to organise a round table session with experts.
This round table session took place on the 19th of January. Ecophon organised the meeting supported by NAG (Dutch Acoustic Society) and NVBV (Dutch Flemmish Building physics Assocation). 20 acousticians were invited and they all participated.
Together with Lau Nijs http://bk.nijsnet.com/ and Martin ten Pierik of TU/Delft we worked out a programme and a questionnaire which was sent to all participants a few weeks before to highlight the areas for discussion. This was filled in by all participants which shows the huge commitment to the subject!
Sports hall questionnaire pdf in english: Download file here
Click here for guideline in dutch
12.30 - Welcome and lunch, presentations of outcomes questionnaires by Guus Klamerek
13.00 - Case 1 by Jeroen Vugts, LBP Sight http://www.lbpsight.nl/medewerkers/49/
14.00 - Workshop on 6 statements
16.00 - Case 2 by Gerard Dethmers, Buro Nieman
17.00 - Evaluation with fingerfood and drinks
We had some very interesting discussions going on. We have a pretty strict practical guideline in Holland called NOC*NSF ISA-US-BF1. It is based on RT and volumes. This guideline was discussed and everyone agreed that some adjustments can be done to improve it.
Questionnaire and statements:
- 10 people use Sabine equation to calculate RT in sports halls
- 9 people use a ray tracing model
- 3 people use Eyring
- On the question which method do you trust most only one person said Sabine. 8 people said they trust a ray tracing model the most.
- Absorbing materials are in most cases chosen together with the architect
- Most of the acousticians give experienced based advice. Also with ray tracing it is very important to have some experience. Also the specs of the materials given by the producer determines the outcomes of ray tracing.
- Possible parameters to add to the ISA norm:
STI, G, C50, EDT
- Are flutterechoes disturbing? And if when? What should one do with the flutters?
- Should we use T20. T30 or EDT?
- A sports hall should not be over damped.
At the end of the session we concluded that there still are some question marks. We decided to make a project group who will have a look at if and how we can let a student do a study so that we possibly can change the standard.
Project group participants:
Renz van Luxemburg, TU/ Eindhoven, Level Acoustics
Lau Nijs/ Martin Tenpierik, TU/ Delft
Jeroen Neggers, ISA Sport
Maarten Luykx, Peutz
Monika Rychtarikova, KU Leuven
Guus Klamerek, Ecophon