A. P. Carvalho and C. C. Barreira Proceedings of Meetings on Acoustics Volume 21, 2014 http://acousticalsociety.org/ 167th Meeting of the Acoustical Society of America Providence, Rhode Island 5 - 9 May 2014 Session 3pSA: Structural Acoustics and Vibration 3pSA5. Sound and noise in high school gymnasiums Antonio P. Carvalho* and Carla C. Barreira​ ​ *Corresponding author's address: Laboratory of Acoustics, University of Porto, FEUP, Porto, P-4200-465, Porto, Portugal, [email protected] The goal of this research was to characterize the interior acoustics of high school sports facilities using objective parameters. In situ measurements were done in 68 school gymnasiums in Portugal (Volume from 450 to 16,190 m3 with a median of 4,720 m3) regarding LAeqBN (background noise without gym classes), LAeqPE (ongoing Physical Education classes), RT, and RASTI. The results for LAeqBN were from 30 to 59 dB with a median of 42 dB. For the LAeqPE were found values from 68 to 90 dB with a median of 80 dB. For the RT(500/1k/2k), room values from 2.5 to 8.1 s with a median of 4.8 s, were measured. The room average RASTI values were from 0.26 to 0.54 with a median of 0.34. These sports rooms proved to be highly reverberant, almost without sound absorbing materials, which might be harmful, especially for the PE teachers. The subjective perception of the teachers was analyzed through questionnaires where it was verified that they feel most discomfort when it comes to noise conditions. This was supported by the objective results obtained. A multicriteria method to assess the overall acoustic quality of school gymnasiums is presented. Ideal values for those acoustic parameters are presented. Published by the Acoustical Society of America through the American Institute of Physics © 2014 Acoustical Society of America [DOI: 10.1121/1.4875899] Received 24 Apr 2014; published 30 Apr 2014 Proceedings of Meetings on Acoustics, Vol. 21, 065001 (2014) Page 1 Redistribution subject to ASA license or copyright; see http://acousticalsociety.org/content/terms. Download to IP: 193.136.33.217 On: Mon, 12 May 2014 17:22:36 A. P. Carvalho and C. C. Barreira 1 - INTRODUCTION Physical education (PE) teachers spend their entire professional life in a particular type of school environment that is acoustically challenged. The main objective of this work is to characterize the interior acoustics of high schools sports facilities using objective acoustic parameters by in situ measurements. A secondary goal is to assess the subjective perceived quality of those spaces by PE teachers using questionnaires [1]. This study also formulates an “acoustical” overall classification for high school gymnasiums regarding their aptitude and acoustic quality. 2 - THE SAMPLE The sample used was a set of 68 sports facilities in 50 high schools in the Portuguese coast-central coast region of Aveiro (Table 1 and Figures 1 to 9). Some schools have two gymnasiums of different dimensions. This sample is characterized by the architectonic parameters: Length (m), Width (m), Average height (m), Area (m 2), and Volume (m 3) as summarized in Table 2. Figure 1 - Map of the sample used (50 schools) within the Aveiro district (coast-central Portugal) [1]. Table 2 - Statistical summary of the dimensions of the 68 gymnasiums tested. Parameter Length (m) Width (m) Avg. Height (m) Area (m 2) Volume (m 3) Minimum 10.2 9.3 4.3 98 450 Median 30.5 18.1 8.0 553 4720 Mean 30.8 19.7 7.5 664 6290 Maximum 53.2 32.5 12.3 1445 16190 St. deviation 12.5 5.6 2.0 413 4755 Proceedings of Meetings on Acoustics, Vol. 21, 065001 (2014) Page 2 Redistribution subject to ASA license or copyright; see http://acousticalsociety.org/content/terms. Download to IP: 193.136.33.217 On: Mon, 12 May 2014 17:22:36 A. P. Carvalho and C. C. Barreira Table 1 – Sample of schools tested (68 gymnasiums in 50 schools) in Portugal [1]. School Gym geometry (m) 1 EB 2,3 Aires Barbosa, Esgueira 30x18x8 16x14x5 2 ES/3 Jaime Magalhães Lima, Esgueira 44x27x9 - 3 ES/3 Dr. Mário Sacramento, Glória - 20x12x6 4 ES Homem Cristo, Glória - 23x10x5 5 EB 2,3 João Afonso de Aveiro 40x20x9 - 6 EB 2,3 São Bernardo, Aveiro 30x18x8 16x14x5 7 EB 2,3 Castro Matoso, Oliveirinha 30x18x8 16x14x5 8 EB I Eixo 30x18x8 16x14x5 9 EB 2,3 Aradas 45x27x9 16x14x5 10 EB 2,3 Cacia 30x18x8 16x14x5 11 ES/3 Dr. João Celestino Gomes 40x20x9 - 12 EB 2,3 Ílhavo 27x21x9 - 13 EB 2,3 Gafanha da Encarnação 48x23x12 - 14 EB 2,3 Gafanha da Nazaré 50x29x10 - 15 ES/3 Gafanha da Nazaré 44x27x9 - 16 EB 2,3 + ES/3 de Vagos 49x27x12 14x9x4 17 EB 2 Albergaria-a-Velha 30x18x8 16x14x5 18 ES/3 Albergaria-a-Velha 40x20x9 - 19 EB 2,3 Branca 53x24x10 10x10x5 20 EB I São João de Loure 30x18x8 16x14x5 21 ES/3 Estarreja, Beduíno 44x27x9 - 22 EB 2,3 Padre Donaciano de Freire 30x18x8 16x14x5 23 EB 2,3 Dr. Egas Moniz, Avanca 45x26x11 - 24 EBI, JI Pardilhó 30x18x8 16x14x5 25 EB 2,3 Padre António Morais da Fonseca, Murtosa 45x27x9 16x14x5 26 EBI/JI Torreira 45x27x9 16x14x5 27 EB 2,3 Fernando Caldeira, Águeda 40x20x9 - 28 ES/3 Adolfo Portel, Águeda 40x20x9 - 29 ES Marques de Castilho, Águeda - 22x14x7 30 EB 2,3 Aguada de Cima 43x23x10 - 31 EB 2,3 Fermentelos 45x27x9 16x14x5 32 EB 2,3 Valongo do Vouga 30x18x8 16x14x5 33 EB 2,3 + ES/3 Sever do Vouga 45x26x10 - 34 ES Mealhada - 21x17x7 35 EB 2,3 Pampilhosa do Botão 50x28x8 - 36 EB 2,3 Oliveira do Bairro 40x20x9 - 37 ES Oliveira do Bairro 44x27x10 - 38 EB 2,3 Dr. Fernando Peixinho, Oiã - 14x14x6 39 EB 2,3 António Dias Simões, Ovar 40x20x9 - 40 EB 2,3 Florbela Espanca, Esmoriz 40x20x9 - 41 ES Júlio Dinis, Ovar 44x27x9 - 42 EB 2,3 Maceda 30x18x8 16x14x5 43 EB 2,3 Mons. Miguel Oliveira, Válega 30x18x8 16x14x5 44 ES Esmoriz 44x27x9 - 45 EBI S. Vicente de Pereira de Jusã 30x18x8 16x14x5 46 EB 2,3 Anadia 40x20x9 - 47 ES Anadia 25x22x6 18x22x5 48 EB 2,3 Vilarinho do Bairro 44x22x8 - Proceedings of Meetings on Acoustics, Vol. 21, 065001 (2014) Page 3 Redistribution subject to ASA license or copyright; see http://acousticalsociety.org/content/terms. Download to IP: 193.136.33.217 On: Mon, 12 May 2014 17:22:36 A. P. Carvalho and C. C. Barreira Figures 2 and 3 – Sports facilities n. 3 and n 4. Figures 4 and 5 - Sports facilities n. 8 and n. 9. Figures 6 and 7 - Sports facilities n. 31 and n. 40. Proceedings of Meetings on Acoustics, Vol. 21, 065001 (2014) Page 4 Redistribution subject to ASA license or copyright; see http://acousticalsociety.org/content/terms. Download to IP: 193.136.33.217 On: Mon, 12 May 2014 17:22:36 A. P. Carvalho and C. C. Barreira Figures 8 and 9 - Sports facilities n. 42 and n. 44. 3 - METHOD The acoustic parameters measured in situ were: - LAeq BN, Sound pressure levels of the background noise, without Physical Education (PE) classes or any other activity or occupation. One measuring position was used (during five minutes) in each of the 68 gyms tested (Figure 10). Every measurement was made at a height of 1.3 m. - L Aeq PE, Sound pressure levels with ongoing PE classes. One or two measuring positions were used (during five minutes) in the 68 gyms tested (Figure 11) and, in each, during five minutes. Every measurement was made at a height of approximately 1.3 m. - Reverberation Time (s) from 125 to 4k Hz (octave bands) using EN ISO 3382 [2]. Three measuring positions (Figure 12) were used in each of the 14 gyms tested. In each position two readings were done changing 30º the microphone angle. The final result at each position was the RT arithmetic average. Every measurement was made at a height of approximately 1.3 m. - RASTI (Rapid Speech Transmission Index) was measured in 8 or 5 positions according with the gym size (Figures 13 and 14) and, in each, with three readings of 32 s each (sound source at 1.5 m high). 1/4 axis 1/4 axis 1/4 1/4 1 1/2 1 1/2 2 3/4 3/4 3 Figure 10 - LAeq_BN (Background Figure 11 – LAeq_PE (during PE classes) Noise, no occupation) measuring measuring positions - large gyms (in smaller positions. gyms position 3 was not measured). Proceedings of Meetings on Acoustics, Vol. 21, 065001 (2014) Page 5 Redistribution subject to ASA license or copyright; see http://acousticalsociety.org/content/terms. Download to IP: 193.136.33.217 On: Mon, 12 May 2014 17:22:36 A. P. Carvalho and C. C. Barreira The equipment used was a sound level meter B&K 2260, a sound source B&K 4224 and a RASTI set B&K 4225/4419. 1/4 axis 1/4 axis 1/4 axis SS SS SS 1 1/4 1 1/4 6 1/4 1 2 4 1/2 2 1/2 7 3 1/2 22 5 4 3 3/4 3/4 3/4 3 8 5 Figure 12 - RT measuring Figure 13 - RASTI measuring Figure 14 - RASTI measuring positions (SS - sound source). positions (SS - sound source) - positions (SS - sound source) - larger gyms. smaller gyms. 9 95 8 Máximo 85 7 75 6 Q3 5 65 LAeq_ BN (dB) Mediana LAeq_ PE (dB) 4 55 3 Q1 Mínimo 45 2 1 35 0 25 Figure 15(left) - Typical box and whiskers plot.