The document discusses Yvonne Wattez's graduation project which focuses on researching the acoustical behavior of Frenger panels in sports halls. It provides background on issues with acoustics in sports halls, including complaints from PE teachers about voice and hearing problems. Standards for reverberation time in sports halls are presented. Different formulas for calculating reverberation time, such as Sabine, Eyring, Kosten and Fitzroy, are discussed and charts show measurements diverging from calculations.

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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