Noise Pollution and Classroom Acoustics

1. Noise Pollution and Classroom Acoustics Marc Hodapp Rory Moulton Kari Ricker

2. Goals • Original goal • Determine noise levels in local classrooms • Final goals • Improve local classroom acoustics • Develop noise reducing materials using recyclable resources

3. Objectives • Objectives • Determine existing local classroom acoustical conditions • Make recommendations to improve local classrooms • Develop innovative acoustical treatments from recycled material that would also apply to other similar buildings

4. Negative Effects of Poor Classroom Acoustics • 25% to 30% of teacher’s verbal communication is not heard • Lowered reading comprehension scores • Achievement scores below grade levels

5. Reading Comprehension UK, Spain, & Netherlands, 2003 100 Reading Comprehension Scores 0 Aircraft Noise, dB(A) Modified from http://aje.oxfordjournals.org/cgi/content/full/163/1/27 n = 2000 students

6. Standardized Grade Equivalent TestLos Angeles, CA, 2001 Modified From http://www.quietclassrooms.org/library/ICA2001.htm n = 1406 students

7. Population Distribution

8. Methodology Part One:Researching • Archival research • Researched effects of excessive noise • Researched current acoustical solutions • Investigated recycled materials on island • Interviews • Acoustical Engineer • Waste Management Specialist • Industrial Engineer • Mechanical Engineer

9. Methodology Part Two:Selecting Classrooms • Obtained permission from the Puerto Rico Department of Education • Visited four local junior high schools • Located two classrooms in each school • One classroom in noisiest section of school • One classroom in quietest section of school

10. Methodology Part Three:Noise Measurements • Following ANSI standards • Used A-weighted time averaging sound level meter • A-weighted: Noise as perceived by humans • Recorded six separate readings of noise levels • Every three seconds for thirty seconds • Noted background noises during noise level spikes

11. Methodology Part Three:Noise Measurements • In all visited schools • Recorded two unoccupied classrooms • One reading with unoccupied adjacent rooms • One reading with occupied adjacent rooms • In one visited school • Measured an additional room • With air conditioner on • With air conditioner off

12. Methodology Part Four:Classroom Profiling • Outdoors • Photographed school grounds • Measured distances to noise sources • Indoors • Calculated reverberation time • Measured classroom dimensions • Noted classroom objects’ material • Distributed teacher surveys

13. Understanding the Results • Noise • Originates from inside or outside • Travels as a sound wave • Measured in decibels (dB) • Classroom levels should be less than 35 dB on average

14. Understanding the Results • Reverberation time (echo) • Can be estimated • Assuming Sabine room • Using absorption coefficients • Can be measured • Using a sound level meter • Units are in seconds • Classroom time should be less than .6 seconds

15. Reverberation Example www.reverberationtime.com

16. Rafael Martinez Nadal (RMN) • Located in Guaynabo • Surrounding the school: • Bus station • High traffic road (most noise) • Farm • Courtyard

17. Dr. Cesareo Rosa Nieves (CRN) • Located in the San Juan area • Surrounding the school: • Construction site on two sides (most noise) • Elementary school • Housing

18. Sabana Llana (SL) • Located in the San Juan area • Surrounding the school: • High traffic street (most noise) • Courtyard with a basketball court (most noise) • Housing • Parking lot

19. Republica Del Peru (RDP) • Located in the San Juan area • Surrounding the school: • High traffic road (most noise) • Housing on two sides • Basketball court and playing fields

20. Results

21. ResultsRafael Martinez Nadal Room 1 Adjacent Room Occupied

22. ResultsRafael Martinez Nadal Classroom Comparison Chart

23. Results

24. Results

25. Results

26. Teacher Results

27. Teacher Results • 98 percent reported that there was outdoor noise during class hours • 89 percent reported that they have to speak over the outdoor noises • 76 percent recorded that they hear noise from other classrooms • 73 percent recorded that they have to speak over interior noises

28. Teacher Results

29. Conclusions: Classroom Acoustics • Sound levels exceed ANSI, 2005 recommendations • Reverberation times exceed ANSI, 2005 recommendations • People cause the most frequent increases in noise levels • Noise levels vary within schools • Teachers in all schools agree that noise levels are high

30. ResultsSound Absorbing Material • Polyester as a sound absorber http://kr.gobizkorea.com/att/english/offer/PSF-HC1.jpg

31. ResultsSound Absorbing Material

32. ResultsSound Absorbing Material

33. ResultsSound Absorbing Material

34. Conclusions: Acoustical Tiles • Inexpensive fibers • Low initial investment • Pioneering production • Potential for profit • Potentially large market

35. Recommendations for The Department of Education • Phase Number One: Understanding Noise • Purchase low-cost sound level meters • Initiate an island wide sound study • Collect data in a standardized manner • Identify the schools and areas with the most noise problems

36. Recommendations for The Department of Education • Phase Number Two: Developing Standards • Consult an Acoustical Engineer • Develop and adopt acoustical standards • Follow ANSI • Develop standards for Puerto Rico

37. Recommendations for The Department of Education • Phase Number Three: Beginning the Process of Change • Urge schools to consider our low-cost solutions • Consider allocating funds to acoustically treat classrooms • Work with the Environmental Quality Board to reduce noise outside of schools

38. Recommendations for All Puerto Rican Public Schools • Step Number One: Know Your Noise • Take sound level measurements • Interactive learning experience • Involve students and teachers • Locate the loudest and quietest sections • Identify the major sources of noise

39. Recommendations for All Puerto Rican Public Schools • Step Number Two: Involving Students • Educate students about noise • Demonstrate different sound levels in class • Inform students when their voices are loud

40. Recommendations for All Puerto Rican Public Schools • Step Number Three: Designate Quiet Zones • Determine which areas are quiet zones • Hallways • Classrooms • Libraries • Designate one or two break rooms • Located in loudest section • Designate a gathering area outdoors • Located as far away from classes as possible

41. Recommendations for All Puerto Rican Public Schools • Step Number Four: Sound Solutions • Low Cost • Open windows • Close doors • Limit use of mechanical devices • Commercial Solutions • Install acoustical tiles • Seal windows • Install central air conditioning

42. Summary of Recommendations • Locate noise sources • Rearrange classrooms • Educate students about noise • Seperate break areas from classes • Open windows to reduce reverberation • Limit the use of mechanical devices

43. Thank you • Department of Education • University of Puerto Rico • Selected schools • Interviewees • ADS • PRIDCO • REMA