Investigations of the relationships between unoccupied classroom acoustical conditions and elementary student achievement

Current building standards recommend specific unoccupied background noise levels and reverberation times for classroom spaces. While clear communication in elementary school classrooms may be critical for successful learning environments, the existing research does not show a consistent connection between the classroom acoustics parameters specified in building standards and student achievement. This research seeks to determine what acoustical conditions should be attained in elementary school classrooms to optimize student achievement. In this dissertation, acoustical studies in two midwestern United States public school systems are described. Unoccupied background noise level (BNL) and reverberation time (RT) measurements were gathered in a range of elementary school classrooms (125 total). Additionally, detailed binaural room impulse response (BRIR) measurements were gathered in 24 of these classrooms. For the BRIR measurements, a source loudspeaker with a directivity pattern similar to that of a human talker was used. The loudspeaker was placed at the front of each room at varying rotation angles to simulate a teacher facing different directions while speaking to the class. Multiple receiver positions at typical student locations were used in each classroom. The metrics calculated from the BRIR measurements include perception-based parameters, such as speech transmission index (STI), distortion of frequency-smoothed magnitude (DFSM), interaural cross-correlation (IACC), and interaural level difference (ILD). The results from this research suggest that elementary student reading and language subject areas may be negatively impacted by higher unoccupied BNLs. Also, classrooms with lower DFSMs generally had students with higher language achievement scores. However, the classrooms included in the study had a limited range of RTs. Therefore, further investigations are needed in classrooms with longer RTs to fully assess the relationships between classroom acoustical conditions and student achievement. Advisor: Lily M. Wan

AB-10-C037: Effects of noise from building mechanical systems on elementary school student achievement

This project seeks to determine what relationship, if any, exists betweenbackground noise levels in elementary classrooms due to the building mechanicalsystems and student performance on achievement tests. Previous research inclassroom acoustics has clearly identified that lower background noise levelsresult in higher speech intelligibility which is crucial for the learning process;however, there is a lack of data correlating lower noise levels to improved studentachievement scores. For this study, background noise level measurements were madein 14 elementary schools in a public school system in Council Bluffs, Iowa, USA.The measurements were made in unoccupied classrooms with the central buildingmechanical systems activated. Second and fourth-grade classrooms were included inthe study, which typically contain 7 to 8 and 9 to 10 year-old students,respectively. The unoccupied noise levels measured in the analyzed classroomsrange from 36 – 50 dBA, none of which meets the background noise levelrecommendation of 35 dBA or less specified for classrooms in ANSI S12.60-2002(R2009). These measured background noise levels have been correlated toreading comprehension and math standardized achievement test scores from studentsin the surveyed classrooms. Poverty rates were used as a control variable for thecorrelation analyses to factor out some of the socio-economic differences among thestudents. ANOVA and regression analyses were also performed to determine iflearning for the younger and older students was impacted similarly by mechanicalsystem noise and what background noise level should be attained in classrooms tomeet state learning achievement goals. The results from this study show that, forthe elementary school system tested, lower student reading comprehension scoreswere significantly related to higher background noise levels from buildingmechanical systems

Relationships between unoccupied classroom acoustical conditions and elementary student achievement measured in eastern Nebraska

Building standards recommend maximum background noise levels (BNL) and reverberation times (RT) for unoccupied classrooms. However, existing research does not show a consistent correlation between these parameters and student achievement. Through in situ testing, this research seeks to determine what acoustical conditions should be attained in elementary schools for students to meet educational goals. Acoustical measurements were conducted in a Nebraska public school system and correlated to achievement scores from students in the surveyed classrooms. Unoccupied BNLs and RTs were gathered in 34 third and 33 fifth-grade classrooms. Additionally, binaural room impulse response measurements were gathered in a subset of the classrooms. The results suggest that student reading and language subject areas may be negatively impacted by higher unoccupied BNLs; to meet the upper half of NE state targets, these levels should be less than 45 dBA. However, the percentage of students receiving free or reduced price lunches is more strongly correlated to achievement than BNLs, and the negative correlations between noise and achievement are not significant when controlling for this demographic variable. One statistically significant relationship that remained when controlling for demographics was that classrooms with lower distortion of frequency-smoothed magnitude values generally had students with higher language scores

Examining the Relationships between Monaural and Binaural Classroom Acoustics Parameters and Student Achievement

This study investigates the relationships between several classroom acoustics parameters and student achievement. Detailed binaural room impulse response measurements were conducted in four elementary school classrooms in a midwestern public school system in the United States. Unoccupied background noise levels were also recorded in these spaces. Previous studies have compared how different room acoustics metrics predict speech intelligibility, while another investigation examined perception-based binaural metrics in a typical classroom. This study extends these previous research areas by comparing both binaural classroom acoustics metrics and unoccupied background noise levels to each other and to the standardized student achievement scores of students in the surveyed classrooms. The binaural metrics examined include interaural level differences, interaural cross-correlations, and comparisons of the speech transmission index and frequency-to-frequency fluctuations between the two ears. The results will indi-cate which classroom acoustics parameters, if any, are most strongly related to student achievement

Industry Participation in the Interdisciplinary Team Design Project Course of a Master of Architectural Engineering Program

This is a case study of extensive industry participation in the capstone design course of the Master of Architectural Engineering program at the University of Nebraska – Lincoln. This course, entitled Interdisciplinary Team Design Project, pairs teams of professional engineers and students to provide mentoring, assessment, and feedback, as the students work on interdisciplinary teams to design the building systems for a real-world project. For the spring 2010 semester, over 33 industry professionals participated in the course, each contributing approximately 40 to 50 hours of mentoring and assessment. This paper describes the course format and industry involvement, which provides students with invaluable, hands-on learning experiences