1. ACOUSTICS IN SPORTS HALLS
research on the acoustical behaviour of Frenger panels
Presentation P1
11/11/2011
Graduation project of Yvonne Wattez
Student nr. 1360809
Building Technology | Green Building Innovation
Faculty of Architecture | TU Delft
Mentor 1: Martin Tenpierik
Mentor 2: still unknown

2. ACOUSTICS IN SPORTS HALLS Yvonne Wattez 1360809 graduation project
research on the acoustical behaviour of Frenger panels P1 presentation 11/11/2011
Why?
I like sports.
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3. ACOUSTICS IN SPORTS HALLS Yvonne Wattez 1360809 graduation project
research on the acoustical behaviour of Frenger panels P1 presentation 11/11/2011
Why?
I like sports.
I like acoustics.
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4. ACOUSTICS IN SPORTS HALLS Yvonne Wattez 1360809 graduation project
research on the acoustical behaviour of Frenger panels P1 presentation 11/11/2011
Why?
I like sports.
I like acoustics.
Acoustics in sports halls seem to be
a problem.
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5. ACOUSTICS IN SPORTS HALLS Yvonne Wattez 1360809 graduation project
research on the acoustical behaviour of Frenger panels P1 presentation 11/11/2011
Problem?
Complaints of PE teachers:
- voice problems,
- hearing problems,
- tiredness.
Mainly caused by bad acoustics of
sports halls.
- reverberation time,
- background noise,
- speechintelligibility.
Teachers need to shout to make
themselves heard.
Pictures:
Protest action in Rijssen - Holten.
[source: tcturbantia 27 sept 2010]
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6. ACOUSTICS IN SPORTS HALLS Yvonne Wattez 1360809 graduation project
research on the acoustical behaviour of Frenger panels P1 presentation 11/11/2011
Standards
Based on reverberation time [T] and
sound pressure level.
Average: between 1,2 and 1,8 sec
Max: between 1,5 and 2,2 sec
depending on size and volume.
[source: ISA Sport, Handboek sportaccomodaties]
picture: sports hall in Amstelveen
[source:www.sportbedrijfamstelveen.nl]
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7. ACOUSTICS IN SPORTS HALLS Yvonne Wattez 1360809 graduation project
research on the acoustical behaviour of Frenger panels P1 presentation 11/11/2011
Sabine Reverberation time
Calculations vs. measurements.
Calculations: formula of Sabine.
[source: ISA-Sport (2002)]
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8. ACOUSTICS IN SPORTS HALLS Yvonne Wattez 1360809 graduation project
research on the acoustical behaviour of Frenger panels P1 presentation 11/11/2011
Eyring Reverberation time
Calculations vs. measurements.
Calculations: formula of Sabine.
Other formulas to calculate [T]:
Eyring,
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9. ACOUSTICS IN SPORTS HALLS Yvonne Wattez 1360809 graduation project
research on the acoustical behaviour of Frenger panels P1 presentation 11/11/2011
Kosten Reverberation time
Calculations vs. measurements.
Calculations: formula of Sabine.
Other formulas to calculate [T]:
Eyring, Kosten,
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10. ACOUSTICS IN SPORTS HALLS Yvonne Wattez 1360809 graduation project
research on the acoustical behaviour of Frenger panels P1 presentation 11/11/2011
Fitzroy Reverberation time
Calculations vs. measurements.
Calculations: formula of Sabine.
Other formulas to calculate [T]:
Eyring, Kosten, Fitzroy.
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11. ACOUSTICS IN SPORTS HALLS Yvonne Wattez 1360809 graduation project
research on the acoustical behaviour of Frenger panels P1 presentation 11/11/2011
Formulas compared: Reverberation time
sports hall Nieuwleusen: stone walls
Calculations vs. measurements.
Calculations: formula of Sabine.
Other formulas to calculate [T]:
Eyring, Kosten, Fitzroy.
Chart: formulas show considerable
difference compared to the
measurement.
sports hall Schijndel: perforated steel panels on walls
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12. ACOUSTICS IN SPORTS HALLS Yvonne Wattez 1360809 graduation project
research on the acoustical behaviour of Frenger panels P1 presentation 11/11/2011
Reverberation time
Nagalmtijd Calculations vs. measurements.
Gymzaal (21 x 12 x 6 m) High peek around 500Hz could be
Meting vs berek ening caused by flutters.
2.5
2.0
Tgem = 1,6 s
1.5
RT [s]
Tgem = 1,0 s
1.0
0.5 Tgem = 0,8 s
0.0
125 250 500 1000 2000 4000
f [Hz]
T20-meting T-Sabine norm
[source: Vugts, J. (2008) LBP|SIGHT via nvbv.org]
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13. ACOUSTICS IN SPORTS HALLS Yvonne Wattez 1360809 graduation project
research on the acoustical behaviour of Frenger panels P1 presentation 11/11/2011
Flutters
Reflecting sound in between
parallel walls.
De nagalmtijd als te berek
in het ontwerp
90 m = 2 x zaallengte
[source: Vugts, J. (2008) LBP|SIGHT via nvbv.org]
Sportzaal (32x24x7,8 m)
– Norm: Tgem = 1,5 s; Tmax/fb = 2,1 s
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14. ACOUSTICS IN SPORTS HALLS Yvonne Wattez 1360809 graduation project
research on the acoustical behaviour of Frenger panels P1 presentation 11/11/2011
Sound absorption
Remarkable differences in a:
‘Berekende’ geluidabsorptiecoëfficiënt De nagalmtijd in relatie t
(not only in frequencies with possible flutters)
Gymzaal (21 x 12 x 6 m)
- stonevan de geluidabsorptie
walls,
Meting vs berek ening
- soundSporthal (48x28x9 m)
absorbing panels.
0.6
α ‘aanwezig’ (seem to behave ‘better’ = 1,9 s; Tmax/fb = 2,7 s
- Norm: Tgem in low frequencies)
0.5
0.4
The sound absorbing panels seem
α ‘norm’
to behave different than expected
α [-]
0.3
from laboratory measurements.
0.2
α ‘gemeten’
0.1
0.0
125 250 500 1000 2000 4000 3 varianten met gelijke hoeveelheid geluidabs
f [Hz] • Variant 1: Wandabsorptie rondom bovens
Research question!Wandabsorptie rondom onderst
• Variant 2:
T20-meting T-Sabine norm
• Variant 3: Wandabsorptie twee hele wand
[source: Vugts, J. (2008) LBP|SIGHT via nvbv.org]
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15. ACOUSTICS IN SPORTS HALLS Yvonne Wattez 1360809 graduation project
research on the acoustical behaviour of Frenger panels P1 presentation 11/11/2011
Research question Frenger panels are a common
type of perforated steel absorption
panels.
Why do Frenger sound absorbing ceiling/wall panels seem to
behave differently in absorption coefficient in sports halls than
expected from laboratory test results?
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16. ACOUSTICS IN SPORTS HALLS Yvonne Wattez 1360809 graduation project
research on the acoustical behaviour of Frenger panels P1 presentation 11/11/2011
Objective
1. Determining whether or not a difference in sound
absorption behaviour of Frenger panels exists between practical
applications and lab situations.
2. If no difference exist, understanding what causes the
differences in results.
3. If a difference exists, understanding what causes this
difference in behaviour.
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17. ACOUSTICS IN SPORTS HALLS Yvonne Wattez 1360809 graduation project
research on the acoustical behaviour of Frenger panels P1 presentation 11/11/2011
Hypotheses
If there is no difference in sound absorbing behaviour:
• A Frenger panel behaves differently in practice than in
a laboratory situation on absorption coefficient because of a
difference in sound field.
If there is a difference in sound absorbing behaviour:
• A Frenger panel behaves differently in practice than in
a laboratory situation on absorption coefficient, the different
placement of the panel in the laboratory than in practice has
influence on the result.
• A Frenger panel behaves differently in practice than in
a laboratory situation on absorption coefficient because the
backing construction is not taken into account in the laboratory
measurement, it has influence on the result.
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18. ACOUSTICS IN SPORTS HALLS Yvonne Wattez 1360809 graduation project
research on the acoustical behaviour of Frenger panels P1 presentation 11/11/2011
Method Method
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19. ACOUSTICS IN SPORTS HALLS Yvonne Wattez 1360809 graduation project
research on the acoustical behaviour of Frenger panels P1 presentation 11/11/2011
Timeline
decision on more specific topic and
second mentor
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20. ACOUSTICS IN SPORTS HALLS Yvonne Wattez 1360809 graduation project
research on the acoustical behaviour of Frenger panels P1 presentation 11/11/2011
Questions?
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