Some years ago, sports halls and gyms were on the news because of their bad acoustics. In 2010, PE teachers and pupils from a school in Rijssen-Holten got publicity because they were using earmuffs while sporting. With this protest action, they wanted to show that the bad acoustics in sports halls was, in their opinion, the cause of their hearing and voice problems. Most of the complaints the PE teachers had were related throat problems, tiredness and hearing problems. Over the last decade, several studies looking into the acoustics in sports halls have been conducted. Some studies indeed found very high noise levels during sporting activities; levels which are highly above the generally accepted arbo levels (80 dB(A)). This indeed may show one of the causes of the complaints of the teachers and pupils.
However, one other important factor makes sports halls special. Many sports halls have sound absorption placed only on the ceiling. Because of impact and ball proofing, the walls are generally made from robust and highly reflecting materials. The result is that the vertical sound field is quickly attenuated and that the horizontal sound field remains. This causes two important issues. First, it is very difficult to perform reliable measurements of the reverberation time, which is a measure of the acoustical quality of the space. Generally, guidelines for sport halls are based on this parameter but it is hard to get a reliable measurement. Second, flutter echoes, which are sound waves reflecting back and forth between two parallel reflecting walls, may become apparent. These flutter echoes generally can be heard as a rattling sound. Whether these are really audible and disturbing all depends on the type of noise source.
This research investigates the issues of reverberation time and other parameters that can reliably be used for assessing the quality of sports halls and the issues of flutter echoes in sports halls.
An important next step in this research involves the use of questionnaires to get a better picture of how sports halls are acoustically perceived by teachers, pupils and professional athletes. The results of these questionnaires can then also be correlated to the results of measurements and simulations to get a clear picture of the characteristics of acoustically good sports halls.
An important part of this research has been and is being conducted by ir. Lau Nijs, retired assistant professor in acoustics at the faculty of Architecture and the Built Environment. Currently, this research is among others also connected to the national task group Acoustics in Sports Halls, which consists of LBP/SIGHT (ir. Jeroen Vugts), Ecophon (Guus Klamerek), M+P (ir. Theodoor Höngens), Peutz (ir. Maarten Luykx), TUDelft (Dr.ir. Martin Tenpierik, ir. Lau Nijs), KULeuven (Dr. Monika Rychtarikova), TUEindhoven / Level Acoustics (ir. Nicole van Hout)
Dr.ir. M.J. Tenpierik (faculty of Architecture and the Built Environment)