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From page 62... ... Appendix E Observational Classroom Study Report Read the entire page →
From page 63... ... Appendix E – Observational Classroom Study Report E-1 ACRP – Draft Results Version: 06/01/17 EXECUTIVE SUMMARY F‐1 1. Description of the sample F‐8 2. Read the entire page →
From page 64... ... Appendix E – Observational Classroom Study Report E-2 Executive Summary OVERVIEW  134 classroom sessions, across eleven schools from two school districts in Los Angeles took part in the study. Classroom sessions were observed for between one to one and a half hours. The schools in the sample were characterized as having high levels of students in receipt of free school meals and who were English Language Learners (ELL) . In most schools over 90% of the students were of Hispanic ethnicity. Read the entire page →
From page 65... ... Appendix E – Observational Classroom Study Report E-3  TA55, TA60 and TA65 varied across the data for the one second, five second, ten second and 30 second metrics.  Internal and external LAeq one second, five seconds, ten seconds and 30 seconds were significantly associated with the onset of voice masking events. Read the entire page →
From page 66... ... Appendix E – Observational Classroom Study Report E-4 suited to this approach, as they indicate the number of noise events across the observation period or in our case, one hour of the observation period. We also carried out this analysis for the TA metrics, as TA is a good method of characterizing exposure over longer periods of the classroom sessions.  For these analyses, no teacher voice masking events were observed in 51% of the sessions, one event was observed in 22% of the sessions, two events were observed in 10% of the sessions, and three or more events were observed in 17% of the sessions.  Internal and external TA metrics were not significantly associated with an increased risk for observing one, two or three or more masking events in a classroom session. Read the entire page →
From page 67... ... Appendix E – Observational Classroom Study Report E-5 associated with larger increases in the risk for voice raising events (33% and 113%) than the NA55 to NA70 metrics, which showed similar increases in risk (9‐15%) Read the entire page →
From page 68... ... Appendix E – Observational Classroom Study Report E-6 Table 1: Summary of where associations were observed between internal noise metrics and the key outcomes Onset of the event Number of the event observed Teacher voice masking events Teacher voice raising events Student dis‐ traction Teacher voice masking events Teacher voice raising events Student dis‐traction Short‐time period metrics LAeq 1 second ✔ ✔ LAeq 5 second ✔ ✔ LAeq 10 second ✔ ✔ LAeq 30 second ✔ ✔ TA 55 5 second ✔ ✗ TA 55 10 second ✔ ✗ TA 55 30 second ✔ ✗ TA 60 5 second ✔ ✔ TA 60 10 second ✔ ✔ TA 60 30 second ✔ ✔ TA 65 5 second ✔ ✔ TA 65 10 second ✔ ✔ TA 65 30 second ✔ ✔ Entire test‐session metrics NA55 ✗ ✔ NA60 ✔ ✔ NA65 ✔ ✔ TA55 ✗ ✔ TA60 ✗ ✔ TA65 ✗ ✔ Read the entire page →
From page 69... ... Appendix E – Observational Classroom Study Report E-7 Table 2: Summary of where associations were observed between external noise metrics and the key outcomes Onset of the event Number of the event observed Teacher voice masking events Teacher voice raising events Student dis‐ traction Teacher voice masking events Teacher voice raising events Student dis‐traction Short‐time period metrics LAeq 1 second ✔ ✗ LAeq 5 second ✔ ✗ LAeq 10 second ✔ ✗ LAeq 30 second ✔ ✗ TA 55 5 second ✔ ✗ TA 55 10 second ✔ ✗ TA 55 30 second ✔ ✗ TA 60 5 second ✔ ✗ TA 60 10 second ✔ ✗ TA 60 30 second ✔ ✗ TA 65 5 second ✔ ✗ TA 65 10 second ✔ ✗ TA 65 30 second ✔ ✗ Entire test‐session metrics NA55 ✔ ✔ NA60 ✔ ✔ NA65 ✔ ✔ TA55 ✗ ✗ TA60 ✗ ✗ TA65 ✗ ✗ Annual LAeq for aircraft noise ✔ ✔ Suggestions for future studies  A preliminary conclusion that can be drawn from the present data is that classroom dynamics, particularly teacher behavior, are associated with fluctuations in external noise. Given the well documented effects of chronic noise exposure from airport noise on children's reading acquisition, an important next step would be to test whether changes in noise‐related teaching behavior (e.g., noise masking, voice raising) can account for some of the noise‐reading relations. Read the entire page →
From page 70... ... Appendix E – Observational Classroom Study Report E-8 approach resulted in only a few student distraction events being observed. This means that if future studies wanted to assess student distraction they would either need to increase the number of observers, so more than one student in the class could be observed at a time and/or observe classes for a longer period of time. Another method that may prove effective for examining student distraction in relation to noise events might be video coding of classroom sessions. 1. Description of the sample This section describes key data from the classroom observation study, characterizing the acute noise exposure of the schools participating in the study during the test sessions, the number of classes, teachers and students observed in the study, and the key outcome events observed. Eleven schools across the two school districts took part in the study. Table 3 describes key data relating to the number of classrooms and the number of students in these classes that made up our sample. Overall, 134 classroom sessions were observed, with the average class size within each school ranging from 18 to 28 students. The number of classroom sessions observed varied per school, ranging from seven to 18 sessions. School size (not students sampled per school) Read the entire page →
From page 71... ... Appendix E – Observational Classroom Study Report E-9 Table 4: Noise mitigation of schools in our sample. School Id Mitigated (No or Yes) 1 No 2 Yes 3 No 4 Yes 5 No 6 No 7 Yes (Underground) Read the entire page →
From page 72... ... Appendix E – Observational Classroom Study Report E-10 Table 6: Percentage of students in the school eligible for free school meals, with English as a second language, and from different ethnic groups. School id % of students eligible for free school meals by school % of students who were English Language Learners in the classes observed Ethnicity % African American % Hispanic % Other 1 92.22 56.07 0.65 99.02 0.33 2 93.00 41.25 0.99 98.02 0.99 3 92.00 36.00 16.53 75.45 8.02 4 92.29 38.90 1.21 97.05 1.73 5 95.20 41.71 1.02 97.51 1.47 6 92.00 38.17 35.36 61.00 3.64 7 92.38 46.00 1.93 96.49 1.57 8 78.33 35.91 11.35 78.32 10.33 9 91.63 43.36 15.74 76.85 7.41 10 92.00 52.38 14.55 81.56 3.89 11 92.57 35.56 31.40 61.97 6.63 2. School‐level acute noise exposure during the test sessions Table 7 shows the internal LAeq noise for each of the schools in the sample, measured during the observation sessions, confirming that internal noise exposure was similar between the schools in the sample. Table 7: Internal LAeq noise during the test sessions by school. School id Mean SD Min Max 1 57.11 8.22 32.17 93.86 2 54.92 8.61 29.68 87.53 3 59.14 8.43 33.02 88.40 4 55.21 7.63 30.65 88.12 5 56.58 8.56 27.65 91.80 6 56.46 7.30 36.67 93.32 7 56.03 7.04 37.28 91.82 8 55.52 8.71 32.10 82.21 9 58.04 6.67 39.41 85.25 10 57.28 7.34 32.75 86.28 11 56.14 8.11 32.58 88.20 SD=standard deviation Table 8 shows the external LAeq noise during the test session for each of the schools in the sample. Average external LAeq during the test sessions ranged from 52dB to 66dB. Read the entire page →
From page 73... ... Appendix E – Observational Classroom Study Report E-11 Table 8: External LAeq noise during the test sessions by school. School id Mean SD Min Max 1 61.80 6.19 50.18 99.25 2 57.31 8.88 41.53 94.54 3 59.39 5.48 47.66 94.30 4 65.65 4.23 56.64 89.06 5 59.10 6.77 47.70 88.31 6 62.25 6.41 46.14 91.40 7 56.90 6.50 44.50 88.81 8 52.99 6.96 41.74 85.50 9 65.49 6.12 50.45 101.52 10 56.09 4.01 45.92 86.77 11 56.57 7.41 42.10 82.10 Table 9 shows the percentage of time during the test sessions in each school that internal noise was above 55, 60 and 65dB. Internal TA55 ranged from 8% to 29%; internal TA60 ranged from 4% to 17%; and internal TA65 ranged from 2% to 7%. Table 9: Internal TA during the test sessions by school School id Internal TA55 Internal TA60 Internal TA65 Mean SD Mean SD Mean SD 1 18.24 7.12 11.56 6.39 5.29 3.95 2 27.34 12.53 16.65 10.51 6.98 7.86 3 8.16 5.09 5.96 4.04 3.26 2.99 4 15.29 5.43 8.34 3.94 2.76 2.02 5 17.10 6.35 10.98 5.54 5.12 3.88 6 8.14 1.26 4.35 2.27 1.93 1.81 7 28.56 12.54 16.55 10.62 7.07 6.52 8 7.91 4.56 5.09 3.72 2.15 2.02 9 8.82 5.91 5.63 4.16 2.24 2.26 10 9.33 4.77 6.53 4.68 3.01 3.12 11 12.42 3.97 6.25 3.85 2.82 3.16 Table 10 shows the percentage of time during the test sessions in each school that external noise was above 55, 60 and 65dB. External TA55 ranged from 6% to 35%; external TA60 ranged from 2% to 26%; and external TA65 ranged from <1%% to 19%. Read the entire page →
From page 74... ... Appendix E – Observational Classroom Study Report E-12 Table 10: External TA during the test sessions by school School id External TA55 External TA60 External TA65 Mean SD Mean SD Mean SD 1 29.90 7.09 22.9 7.18 13.95 4.51 2 33.31 4.02 23.28 6.35 15.34 4.67 3 9.50 5.53 5.79 4.53 2.31 1.99 4 27.42 6.15 25.74 4.39 19.36 3.48 5 24.30 3.62 16.27 2.13 10.66 1.31 6 14.88 3.09 9.97 0.73 5.95 0.52 7 34.62 6.44 24.04 5.38 12.19 2.30 8 6.02 3.54 2.01 2.06 0.46 0.66 9 13.08 7.41 10.27 5.44 6.74 3.99 10 10.14 5.35 3.67 2.24 0.47 0.48 11 15.64 6.65 10.01 5.89 3.77 2.93 3. Key outcomes This section describes the key outcomes that were coded by observers during the classroom observation sessions. 3.1. Teacher – Voice Masking Events Observers coded each time that the teacher's voice was masked by another noise source. Table 11 illustrates the number of masking events observed by school, as well as the mean duration of the masking event in seconds and the percentage of the total time observed that involved masking events. There was a wide range in the number (1‐66) Read the entire page →
From page 75... ... Appendix E – Observational Classroom Study Report E-13 Table 12: Raising voice events by school: number, mean duration and % of time. School id Number of raising voice events Mean duration of raising voice (seconds) % of time raising voice (seconds) Read the entire page →
From page 76... ... Appendix E – Observational Classroom Study Report E-14 1. Analyses comparing noise metrics over short‐time‐periods (1 second, 5 seconds, 10 seconds, 30 seconds) Read the entire page →
From page 77... ... Appendix E – Observational Classroom Study Report E-15  For noise metrics over one second ‐ the percentage of time that aircraft noise was heard and the noise metric threshold was crossed is described.  For noise metrics over five, ten and 30 seconds ‐ the mean number of seconds that the noise metric was met in that time period is described. Read the entire page →
From page 78... ... Appendix E – Observational Classroom Study Report E-16 percent increase in the odds for a voice masking event being observed after adjustment for ethnicity, receipt of free school meals, being an English Language Learner and class subject. Table 16: Adjusted association between internal LAeq and starting a teacher voice masking event, clustered by classroom within school. Adjusted Odds Ratio (95% Confidence Interval) Internal LAeq One second prior to starting masking 1.04* Read the entire page →
From page 79... ... Appendix E – Observational Classroom Study Report E-17 Table 18: Mean internal TA percentage per school 10 seconds prior to teacher starting masking and aircraft can be heard. TA55 10 seconds before masking TA60 10 seconds before masking TA65 10 seconds before masking School ID Mean SD Mean SD Mean SD 1 53.79 43.98 38.64 38.90 18.33 27.93 2 65.33 48.09 55.33 44.70 10.00 16.48 3 12.31 31.13 12.31 31.13 10.00 25.17 4 30.63 41.23 20.00 34.45 10.00 22.21 5 12.50 28.26 10.00 21.76 4.50 13.95 6 0.00 . 0.00 . 0.00 . 7 41.91 43.17 25.74 32.08 7.66 17.09 8 16.38 31.24 7.23 17.78 3.83 10.33 9 25.00 50.00 25.00 50.00 10.00 20.00 10 0.00 0.00 0.00 0.00 0.00 0.00 11 5.00 18.71 3.57 13.36 1.43 5.35 Table 19 shows the percentage of time that internal TA was above 55dB, 60dB, and 65dB 30 seconds prior to a teacher masking event being observed. For the 30 second period, internal TA55 ranged from 0%‐53%, TA60 from 0% to 49%, and TA65 from 0%‐13%. Table 19: Mean internal TA percentage per school 30 seconds prior to teacher starting masking and aircraft can be heard. TA55 30 seconds before masking TA60 30 seconds before masking TA65 30 seconds before masking School ID Mean SD Mean SD Mean SD 1 28.84 23.17 24.65 25.76 11.97 18.64 2 52.89 41.80 49.33 38.98 8.67 8.80 3 15.83 30.92 11.94 27.47 7.50 18.37 4 20.00 21.98 17.29 25.65 6.88 13.90 5 18.67 32.43 11.83 24.84 6.33 17.06 6 0.00 . 0.00 . Read the entire page →
From page 80... ... Appendix E – Observational Classroom Study Report E-18 Table 20: Adjusted association between internal TA and starting a teacher voice masking event, clustered by classroom within school. Adjusted Odds Ratio (95% Confidence Interval) Internal TA>=55 TA55 within 5 seconds prior to starting masking 1.01* Read the entire page →
From page 81... ... Appendix E – Observational Classroom Study Report E-19 Table 22: Adjusted association between external LAeq and starting a teacher voice masking event, clustered by classroom within school. Adjusted Odds Ratio (95% Confidence Interval) External LAeq One second prior to starting masking 1.06* Read the entire page →
From page 82... ... Appendix E – Observational Classroom Study Report E-20 Table 25: Mean external TA percentage per school 10 seconds prior to teacher starting masking. TA55 10 seconds before masking TA60 10 seconds before masking TA65 10 seconds before masking School ID Mean SD Mean SD Mean SD 1 66.36 44.91 63.03 45.03 46.97 44.65 2 54.67 49.41 39.33 42.50 26.67 38.85 3 7.69 27.74 7.69 27.74 1.54 5.55 4 48.13 48.61 45.63 46.76 34.38 40.16 5 26.00 41.73 17.00 33.42 14.50 32.68 6 0.00 . 0.00 . 0.00 . 7 44.26 47.26 31.06 42.80 19.36 33.52 8 17.66 35.15 8.94 21.99 3.40 13.40 9 25.00 50.00 25.00 50.00 2.50 5.00 10 0.00 0.00 0.00 0.00 0.00 0.00 11 9.29 27.31 7.14 26.73 1.43 5.35 Table 26 shows the percentage external TA was above 55dB, 60dB, and 65dB 30 seconds prior to a teacher masking event being observed. For the 30 second period, external TA55 ranged from 0%‐43%, TA60 from 0% to 44%, and TA65 from 0%‐30%. Table 26: Mean external TA percentage per school 30 seconds prior to teacher starting masking. TA55 30 seconds before masking TA60 30 seconds before masking TA65 30 seconds before masking School ID Mean SD Mean SD Mean SD 1 38.03 28.13 43.74 35.64 27.53 28.54 2 42.44 30.98 37.78 27.36 24.67 19.39 3 13.33 31.65 12.78 31.46 7.22 21.17 4 37.50 34.20 42.08 36.75 29.79 31.28 5 24.17 38.10 19.67 32.93 12.50 21.05 6 0.00 . 0.00 . Read the entire page →
From page 83... ... Appendix E – Observational Classroom Study Report E-21 Table 27: Adjusted association between external TA and starting a teacher voice masking event, clustered by classroom within school. Adjusted Odds Ratio (95% Confidence Interval) External TA55 TA55 within 5 seconds prior to starting masking 1.01* Read the entire page →
From page 84... ... Appendix E – Observational Classroom Study Report E-22 Table 29: Adjusted association between internal LAeq and starting a teacher voice raising event, clustered by classroom within school. Adjusted Odds Ratio (95% Confidence Interval) Internal LAeq One second prior to starting raising voice 1.05* Read the entire page →
From page 85... ... Appendix E – Observational Classroom Study Report E-23 Table 31: Mean internal TA percentage per school 10 seconds prior to teacher starting voice raising. TA55 10 seconds before masking TA60 10 seconds before masking TA65 10 seconds before masking School ID Mean SD Mean SD Mean SD 1 23.26 37.61 17.25 32.01 10.07 22.65 2 39.09 43.46 25.45 39.59 12.73 23.70 3 18.75 40.31 18.13 39.02 15.63 34.44 4 11.43 26.10 10.00 22.36 1.43 3.78 5 17.33 36.38 10.67 25.59 7.00 18.41 6 0.00 0.00 0.00 0.00 0.00 0.00 7 37.17 42.90 26.09 33.97 11.20 20.48 8 28.53 40.76 17.94 31.60 11.18 22.80 11 11.76 33.21 11.18 31.60 8.24 23.25 * School 9 removed due to data coding error and school 10 had no raising voice events. Read the entire page →
From page 86... ... Appendix E – Observational Classroom Study Report E-24 Table 33: Adjusted association between internal TA and starting a teacher voice raising event, clustered by classroom within school. Adjusted Odds Ratio (95% Confidence Interval) Internal TA55 TA55 within 5 seconds prior to starting raising voice 1.00 (1.00, 1.01) Read the entire page →
From page 87... ... Appendix E – Observational Classroom Study Report E-25 Table 35: Adjusted association between external LAeq and starting a teacher voice raising event, clustered by classroom within school. Adjusted Odds Ratio (95% Confidence Interval) External LAeq One second prior to starting raising voice 1.01 (0.99, 1.03) Read the entire page →
From page 88... ... Appendix E – Observational Classroom Study Report E-26 Table 38: Mean external TA percentage per school 10 seconds prior to teacher starting voice raising. TA55 10 seconds before masking TA60 10 seconds before masking TA65 10 seconds before masking School ID Mean SD Mean SD Mean SD 1 34.28 45.62 29.49 43.06 19.06 34.58 2 9.09 30.15 2.73 9.05 0.00 0.00 3 18.75 40.31 17.50 37.68 6.25 17.08 4 28.57 48.80 28.57 48.80 20.00 34.64 5 21.33 39.98 15.67 34.81 10.67 28.64 6 0.00 0.00 0.00 0.00 0.00 0.00 7 37.50 44.93 23.80 38.94 11.52 27.81 8 25.59 41.65 15.29 31.84 5.29 15.42 11 7.06 24.43 2.94 12.13 1.18 4.85 * School 9 removed due to data coding error and school 10 had no raising voice events. Read the entire page →
From page 89... ... Appendix E – Observational Classroom Study Report E-27 Table 40: Adjusted association between external TA and starting a teacher voice masking event, clustered by classroom within school. Adjusted Odds Ratio (95% Confidence Interval) External TA55 TA55 within 5 seconds prior to starting masking 1.00 (1.00, 1.00) Read the entire page →
From page 90... ... Appendix E – Observational Classroom Study Report E-28 Table 42: Associations of internal and external TA metrics with the number of teacher voice masking events observed in a session. No masking events in a session One masking event in a session Two masking events in a session Three or more masking events in a session RRR (95%CI) Read the entire page →
From page 91... ... Appendix E – Observational Classroom Study Report E-29 Table 44: Associations of internal and external TA metrics with the number of teacher voice raising events observed in a session. No voice raising events in a session One voice raising event in a session Two or more voice raising events in a session RRR (95%CI) Read the entire page →
From page 92... ... Appendix E – Observational Classroom Study Report E-30 Table 46: Mean and standard deviation (SD) of number of aircraft events observed per hour over a specified threshold when classroom sessions were being observed. Mean (SD) Read the entire page →
From page 93... ... Appendix E – Observational Classroom Study Report E-31 4.8. NA metrics and number of teacher voice raising events This section describes analyses comparing the number of aircraft noise events above set thresholds per hour when a classroom session was being observed, with the number of teacher voice raising events observed in a classroom session per hour. For analyses using the NA noise metrics, the teacher outcome of voice raising events had to be reformatted, as the NA noise metrics were calculated for one‐hour periods. Therefore, the teacher voice raising events were categorized as no events per hour, between 0 and less than one event per hour, and more than one event per hour. For example if in a 1 ½ hour classroom session only one masking event happened then masking per hour would be 1/1.5= 0.67 for this particular session and hence be placed in the between 0 and less than one event per hour group. Table 48 shows that 63% of the classroom sessions observed had no teacher voice raising events per hour; 14% of the classroom sessions had between 0 and less than one teacher voice raising event per hour; and 23% of the classroom sessions had more than one voice raising event per hour. Table 48: Number of teacher voice raising events observed per hour across the classroom sessions. Number of teacher voice masking events observed in the classroom session per hour. Number of sessions % of sessions 0 events per hour 83 63.4 0 < events per hour ≤ 1 18 13.7 More than 1 event per hour 30 22.9 Table 49 shows the association of the internal and external NA metrics with the number of voice raising events observed. These data are shown for one hour intervals in the observation sessions, as the NA metrics are calculated per hour. Table 49 shows that there were consistent significant associations between the internal NA metrics and teacher voice raising events. A one event increase in internal NA55, NA60, NA65, NA70, and NA75 was associated with a 11‐30% increase in the risk for observing 0 to 1 voice raising events, and a 11‐113% increase in the risk for observing more than one voice raising event. Internal NA metrics ranging from NA55 to NA70 were associated with a similar increase in the risk for more than one raising voice event, around a 9 to 15%, increase in risk, whereas NA75 and NA80 were associated with larger increases in risk (33% and 113%, respectively) . A one noise event increase in external NA55, NA60, NA65, NA70, NA75, and NA80 was associated with an 8‐20% increase in the risk for observing 0‐1 voice raising events. A one noise event increase in external NA55, NA60, NA65, and NA70 was associated with a 9‐10% increase in the risk for observing more than one voice raising event. Read the entire page →
From page 94... ... Appendix E – Observational Classroom Study Report E-32 Table 49: Association between internal NA metrics per hour and the number of teacher voice raising events per hour No Raising voice in the hour session 0 < to≤ 1 voice raising events per hour in a session More than 1 voice raising events per hour in a session RRR (95%CI) Read the entire page →
From page 95... ... Appendix E – Observational Classroom Study Report E-33 Table 50: Modelled annual LAeq 24 hours for each school School id Modelled annual LAeq 24 hours (dB) 1 65.5 2 67.4 3 50.5 4 65.6 5 61.9 6 43.7 7 57.2 8 45.7 9 46.4 10 48.4 11 42.6 5.2. Annual LAeq 24 hours and number of teaching voice masking events Table 51 shows the association between the annual average LAeq and the number of teacher voice masking events observed per hour in the classroom observation sessions. The table shows that for each 1dB increase in LAeq 24 hours the risk for observing one to two voice masking events increased by 8% and the risk for observing more than two voice masking events increased by 17%. The data are indicative of a dose‐response relationship between annual LAeq and the risk of voice masking events. We can estimate that a 10dB increase in annual LAeq 24 hours would be associated with an 80% increase in risk for one to two voice masking events (1.08* Read the entire page →

From page 62...

... Appendix E Observational Classroom Study Report

Read the entire page →

From page 63...

... Appendix E – Observational Classroom Study Report E-1 ACRP – Draft Results Version: 06/01/17 EXECUTIVE SUMMARY F‐1 1. Description of the sample F‐8 2.

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From page 64...

... Appendix E – Observational Classroom Study Report E-2 Executive Summary OVERVIEW  134 classroom sessions, across eleven schools from two school districts in Los Angeles took part in the study. Classroom sessions were observed for between one to one and a half hours. The schools in the sample were characterized as having high levels of students in receipt of free school meals and who were English Language Learners (ELL) . In most schools over 90% of the students were of Hispanic ethnicity.

Read the entire page →

From page 65...

... Appendix E – Observational Classroom Study Report E-3  TA55, TA60 and TA65 varied across the data for the one second, five second, ten second and 30 second metrics.  Internal and external LAeq one second, five seconds, ten seconds and 30 seconds were significantly associated with the onset of voice masking events.

Read the entire page →

From page 66...

... Appendix E – Observational Classroom Study Report E-4 suited to this approach, as they indicate the number of noise events across the observation period or in our case, one hour of the observation period. We also carried out this analysis for the TA metrics, as TA is a good method of characterizing exposure over longer periods of the classroom sessions.  For these analyses, no teacher voice masking events were observed in 51% of the sessions, one event was observed in 22% of the sessions, two events were observed in 10% of the sessions, and three or more events were observed in 17% of the sessions.  Internal and external TA metrics were not significantly associated with an increased risk for observing one, two or three or more masking events in a classroom session.

Read the entire page →

From page 67...

... Appendix E – Observational Classroom Study Report E-5 associated with larger increases in the risk for voice raising events (33% and 113%) than the NA55 to NA70 metrics, which showed similar increases in risk (9‐15%)

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From page 68...

... Appendix E – Observational Classroom Study Report E-6 Table 1: Summary of where associations were observed between internal noise metrics and the key outcomes Onset of the event Number of the event observed Teacher voice masking events Teacher voice raising events Student dis‐ traction Teacher voice masking events Teacher voice raising events Student dis‐traction Short‐time period metrics LAeq 1 second ✔ ✔ LAeq 5 second ✔ ✔ LAeq 10 second ✔ ✔ LAeq 30 second ✔ ✔ TA 55 5 second ✔ ✗ TA 55 10 second ✔ ✗ TA 55 30 second ✔ ✗ TA 60 5 second ✔ ✔ TA 60 10 second ✔ ✔ TA 60 30 second ✔ ✔ TA 65 5 second ✔ ✔ TA 65 10 second ✔ ✔ TA 65 30 second ✔ ✔ Entire test‐session metrics NA55 ✗ ✔ NA60 ✔ ✔ NA65 ✔ ✔ TA55 ✗ ✔ TA60 ✗ ✔ TA65 ✗ ✔

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From page 69...

... Appendix E – Observational Classroom Study Report E-7 Table 2: Summary of where associations were observed between external noise metrics and the key outcomes Onset of the event Number of the event observed Teacher voice masking events Teacher voice raising events Student dis‐ traction Teacher voice masking events Teacher voice raising events Student dis‐traction Short‐time period metrics LAeq 1 second ✔ ✗ LAeq 5 second ✔ ✗ LAeq 10 second ✔ ✗ LAeq 30 second ✔ ✗ TA 55 5 second ✔ ✗ TA 55 10 second ✔ ✗ TA 55 30 second ✔ ✗ TA 60 5 second ✔ ✗ TA 60 10 second ✔ ✗ TA 60 30 second ✔ ✗ TA 65 5 second ✔ ✗ TA 65 10 second ✔ ✗ TA 65 30 second ✔ ✗ Entire test‐session metrics NA55 ✔ ✔ NA60 ✔ ✔ NA65 ✔ ✔ TA55 ✗ ✗ TA60 ✗ ✗ TA65 ✗ ✗ Annual LAeq for aircraft noise ✔ ✔ Suggestions for future studies  A preliminary conclusion that can be drawn from the present data is that classroom dynamics, particularly teacher behavior, are associated with fluctuations in external noise. Given the well documented effects of chronic noise exposure from airport noise on children's reading acquisition, an important next step would be to test whether changes in noise‐related teaching behavior (e.g., noise masking, voice raising) can account for some of the noise‐reading relations.

Read the entire page →

From page 70...

... Appendix E – Observational Classroom Study Report E-8 approach resulted in only a few student distraction events being observed. This means that if future studies wanted to assess student distraction they would either need to increase the number of observers, so more than one student in the class could be observed at a time and/or observe classes for a longer period of time. Another method that may prove effective for examining student distraction in relation to noise events might be video coding of classroom sessions. 1. Description of the sample This section describes key data from the classroom observation study, characterizing the acute noise exposure of the schools participating in the study during the test sessions, the number of classes, teachers and students observed in the study, and the key outcome events observed. Eleven schools across the two school districts took part in the study. Table 3 describes key data relating to the number of classrooms and the number of students in these classes that made up our sample. Overall, 134 classroom sessions were observed, with the average class size within each school ranging from 18 to 28 students. The number of classroom sessions observed varied per school, ranging from seven to 18 sessions. School size (not students sampled per school)

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From page 71...

... Appendix E – Observational Classroom Study Report E-9 Table 4: Noise mitigation of schools in our sample. School Id Mitigated (No or Yes) 1 No 2 Yes 3 No 4 Yes 5 No 6 No 7 Yes (Underground)

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From page 72...

... Appendix E – Observational Classroom Study Report E-10 Table 6: Percentage of students in the school eligible for free school meals, with English as a second language, and from different ethnic groups. School id % of students eligible for free school meals by school % of students who were English Language Learners in the classes observed Ethnicity % African American % Hispanic % Other 1 92.22 56.07 0.65 99.02 0.33 2 93.00 41.25 0.99 98.02 0.99 3 92.00 36.00 16.53 75.45 8.02 4 92.29 38.90 1.21 97.05 1.73 5 95.20 41.71 1.02 97.51 1.47 6 92.00 38.17 35.36 61.00 3.64 7 92.38 46.00 1.93 96.49 1.57 8 78.33 35.91 11.35 78.32 10.33 9 91.63 43.36 15.74 76.85 7.41 10 92.00 52.38 14.55 81.56 3.89 11 92.57 35.56 31.40 61.97 6.63 2. School‐level acute noise exposure during the test sessions Table 7 shows the internal LAeq noise for each of the schools in the sample, measured during the observation sessions, confirming that internal noise exposure was similar between the schools in the sample. Table 7: Internal LAeq noise during the test sessions by school. School id Mean SD Min Max 1 57.11 8.22 32.17 93.86 2 54.92 8.61 29.68 87.53 3 59.14 8.43 33.02 88.40 4 55.21 7.63 30.65 88.12 5 56.58 8.56 27.65 91.80 6 56.46 7.30 36.67 93.32 7 56.03 7.04 37.28 91.82 8 55.52 8.71 32.10 82.21 9 58.04 6.67 39.41 85.25 10 57.28 7.34 32.75 86.28 11 56.14 8.11 32.58 88.20 SD=standard deviation Table 8 shows the external LAeq noise during the test session for each of the schools in the sample. Average external LAeq during the test sessions ranged from 52dB to 66dB.

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From page 73...

... Appendix E – Observational Classroom Study Report E-11 Table 8: External LAeq noise during the test sessions by school. School id Mean SD Min Max 1 61.80 6.19 50.18 99.25 2 57.31 8.88 41.53 94.54 3 59.39 5.48 47.66 94.30 4 65.65 4.23 56.64 89.06 5 59.10 6.77 47.70 88.31 6 62.25 6.41 46.14 91.40 7 56.90 6.50 44.50 88.81 8 52.99 6.96 41.74 85.50 9 65.49 6.12 50.45 101.52 10 56.09 4.01 45.92 86.77 11 56.57 7.41 42.10 82.10 Table 9 shows the percentage of time during the test sessions in each school that internal noise was above 55, 60 and 65dB. Internal TA55 ranged from 8% to 29%; internal TA60 ranged from 4% to 17%; and internal TA65 ranged from 2% to 7%. Table 9: Internal TA during the test sessions by school School id Internal TA55 Internal TA60 Internal TA65 Mean SD Mean SD Mean SD 1 18.24 7.12 11.56 6.39 5.29 3.95 2 27.34 12.53 16.65 10.51 6.98 7.86 3 8.16 5.09 5.96 4.04 3.26 2.99 4 15.29 5.43 8.34 3.94 2.76 2.02 5 17.10 6.35 10.98 5.54 5.12 3.88 6 8.14 1.26 4.35 2.27 1.93 1.81 7 28.56 12.54 16.55 10.62 7.07 6.52 8 7.91 4.56 5.09 3.72 2.15 2.02 9 8.82 5.91 5.63 4.16 2.24 2.26 10 9.33 4.77 6.53 4.68 3.01 3.12 11 12.42 3.97 6.25 3.85 2.82 3.16 Table 10 shows the percentage of time during the test sessions in each school that external noise was above 55, 60 and 65dB. External TA55 ranged from 6% to 35%; external TA60 ranged from 2% to 26%; and external TA65 ranged from <1%% to 19%.

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From page 74...

... Appendix E – Observational Classroom Study Report E-12 Table 10: External TA during the test sessions by school School id External TA55 External TA60 External TA65 Mean SD Mean SD Mean SD 1 29.90 7.09 22.9 7.18 13.95 4.51 2 33.31 4.02 23.28 6.35 15.34 4.67 3 9.50 5.53 5.79 4.53 2.31 1.99 4 27.42 6.15 25.74 4.39 19.36 3.48 5 24.30 3.62 16.27 2.13 10.66 1.31 6 14.88 3.09 9.97 0.73 5.95 0.52 7 34.62 6.44 24.04 5.38 12.19 2.30 8 6.02 3.54 2.01 2.06 0.46 0.66 9 13.08 7.41 10.27 5.44 6.74 3.99 10 10.14 5.35 3.67 2.24 0.47 0.48 11 15.64 6.65 10.01 5.89 3.77 2.93 3. Key outcomes This section describes the key outcomes that were coded by observers during the classroom observation sessions. 3.1. Teacher – Voice Masking Events Observers coded each time that the teacher's voice was masked by another noise source. Table 11 illustrates the number of masking events observed by school, as well as the mean duration of the masking event in seconds and the percentage of the total time observed that involved masking events. There was a wide range in the number (1‐66)

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From page 75...

... Appendix E – Observational Classroom Study Report E-13 Table 12: Raising voice events by school: number, mean duration and % of time. School id Number of raising voice events Mean duration of raising voice (seconds) % of time raising voice (seconds)

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From page 76...

... Appendix E – Observational Classroom Study Report E-14 1. Analyses comparing noise metrics over short‐time‐periods (1 second, 5 seconds, 10 seconds, 30 seconds)

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From page 77...

... Appendix E – Observational Classroom Study Report E-15  For noise metrics over one second ‐ the percentage of time that aircraft noise was heard and the noise metric threshold was crossed is described.  For noise metrics over five, ten and 30 seconds ‐ the mean number of seconds that the noise metric was met in that time period is described.

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From page 78...

... Appendix E – Observational Classroom Study Report E-16 percent increase in the odds for a voice masking event being observed after adjustment for ethnicity, receipt of free school meals, being an English Language Learner and class subject. Table 16: Adjusted association between internal LAeq and starting a teacher voice masking event, clustered by classroom within school. Adjusted Odds Ratio (95% Confidence Interval) Internal LAeq One second prior to starting masking 1.04*

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From page 79...

... Appendix E – Observational Classroom Study Report E-17 Table 18: Mean internal TA percentage per school 10 seconds prior to teacher starting masking and aircraft can be heard. TA55 10 seconds before masking TA60 10 seconds before masking TA65 10 seconds before masking School ID Mean SD Mean SD Mean SD 1 53.79 43.98 38.64 38.90 18.33 27.93 2 65.33 48.09 55.33 44.70 10.00 16.48 3 12.31 31.13 12.31 31.13 10.00 25.17 4 30.63 41.23 20.00 34.45 10.00 22.21 5 12.50 28.26 10.00 21.76 4.50 13.95 6 0.00 . 0.00 . 0.00 . 7 41.91 43.17 25.74 32.08 7.66 17.09 8 16.38 31.24 7.23 17.78 3.83 10.33 9 25.00 50.00 25.00 50.00 10.00 20.00 10 0.00 0.00 0.00 0.00 0.00 0.00 11 5.00 18.71 3.57 13.36 1.43 5.35 Table 19 shows the percentage of time that internal TA was above 55dB, 60dB, and 65dB 30 seconds prior to a teacher masking event being observed. For the 30 second period, internal TA55 ranged from 0%‐53%, TA60 from 0% to 49%, and TA65 from 0%‐13%. Table 19: Mean internal TA percentage per school 30 seconds prior to teacher starting masking and aircraft can be heard. TA55 30 seconds before masking TA60 30 seconds before masking TA65 30 seconds before masking School ID Mean SD Mean SD Mean SD 1 28.84 23.17 24.65 25.76 11.97 18.64 2 52.89 41.80 49.33 38.98 8.67 8.80 3 15.83 30.92 11.94 27.47 7.50 18.37 4 20.00 21.98 17.29 25.65 6.88 13.90 5 18.67 32.43 11.83 24.84 6.33 17.06 6 0.00 . 0.00 .

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From page 80...

... Appendix E – Observational Classroom Study Report E-18 Table 20: Adjusted association between internal TA and starting a teacher voice masking event, clustered by classroom within school. Adjusted Odds Ratio (95% Confidence Interval) Internal TA>=55 TA55 within 5 seconds prior to starting masking 1.01*

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From page 81...

... Appendix E – Observational Classroom Study Report E-19 Table 22: Adjusted association between external LAeq and starting a teacher voice masking event, clustered by classroom within school. Adjusted Odds Ratio (95% Confidence Interval) External LAeq One second prior to starting masking 1.06*

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From page 82...

... Appendix E – Observational Classroom Study Report E-20 Table 25: Mean external TA percentage per school 10 seconds prior to teacher starting masking. TA55 10 seconds before masking TA60 10 seconds before masking TA65 10 seconds before masking School ID Mean SD Mean SD Mean SD 1 66.36 44.91 63.03 45.03 46.97 44.65 2 54.67 49.41 39.33 42.50 26.67 38.85 3 7.69 27.74 7.69 27.74 1.54 5.55 4 48.13 48.61 45.63 46.76 34.38 40.16 5 26.00 41.73 17.00 33.42 14.50 32.68 6 0.00 . 0.00 . 0.00 . 7 44.26 47.26 31.06 42.80 19.36 33.52 8 17.66 35.15 8.94 21.99 3.40 13.40 9 25.00 50.00 25.00 50.00 2.50 5.00 10 0.00 0.00 0.00 0.00 0.00 0.00 11 9.29 27.31 7.14 26.73 1.43 5.35 Table 26 shows the percentage external TA was above 55dB, 60dB, and 65dB 30 seconds prior to a teacher masking event being observed. For the 30 second period, external TA55 ranged from 0%‐43%, TA60 from 0% to 44%, and TA65 from 0%‐30%. Table 26: Mean external TA percentage per school 30 seconds prior to teacher starting masking. TA55 30 seconds before masking TA60 30 seconds before masking TA65 30 seconds before masking School ID Mean SD Mean SD Mean SD 1 38.03 28.13 43.74 35.64 27.53 28.54 2 42.44 30.98 37.78 27.36 24.67 19.39 3 13.33 31.65 12.78 31.46 7.22 21.17 4 37.50 34.20 42.08 36.75 29.79 31.28 5 24.17 38.10 19.67 32.93 12.50 21.05 6 0.00 . 0.00 .

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From page 83...

... Appendix E – Observational Classroom Study Report E-21 Table 27: Adjusted association between external TA and starting a teacher voice masking event, clustered by classroom within school. Adjusted Odds Ratio (95% Confidence Interval) External TA55 TA55 within 5 seconds prior to starting masking 1.01*

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From page 84...

... Appendix E – Observational Classroom Study Report E-22 Table 29: Adjusted association between internal LAeq and starting a teacher voice raising event, clustered by classroom within school. Adjusted Odds Ratio (95% Confidence Interval) Internal LAeq One second prior to starting raising voice 1.05*

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From page 85...

... Appendix E – Observational Classroom Study Report E-23 Table 31: Mean internal TA percentage per school 10 seconds prior to teacher starting voice raising. TA55 10 seconds before masking TA60 10 seconds before masking TA65 10 seconds before masking School ID Mean SD Mean SD Mean SD 1 23.26 37.61 17.25 32.01 10.07 22.65 2 39.09 43.46 25.45 39.59 12.73 23.70 3 18.75 40.31 18.13 39.02 15.63 34.44 4 11.43 26.10 10.00 22.36 1.43 3.78 5 17.33 36.38 10.67 25.59 7.00 18.41 6 0.00 0.00 0.00 0.00 0.00 0.00 7 37.17 42.90 26.09 33.97 11.20 20.48 8 28.53 40.76 17.94 31.60 11.18 22.80 11 11.76 33.21 11.18 31.60 8.24 23.25 * School 9 removed due to data coding error and school 10 had no raising voice events.

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From page 86...

... Appendix E – Observational Classroom Study Report E-24 Table 33: Adjusted association between internal TA and starting a teacher voice raising event, clustered by classroom within school. Adjusted Odds Ratio (95% Confidence Interval) Internal TA55 TA55 within 5 seconds prior to starting raising voice 1.00 (1.00, 1.01)

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From page 87...

... Appendix E – Observational Classroom Study Report E-25 Table 35: Adjusted association between external LAeq and starting a teacher voice raising event, clustered by classroom within school. Adjusted Odds Ratio (95% Confidence Interval) External LAeq One second prior to starting raising voice 1.01 (0.99, 1.03)

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From page 88...

... Appendix E – Observational Classroom Study Report E-26 Table 38: Mean external TA percentage per school 10 seconds prior to teacher starting voice raising. TA55 10 seconds before masking TA60 10 seconds before masking TA65 10 seconds before masking School ID Mean SD Mean SD Mean SD 1 34.28 45.62 29.49 43.06 19.06 34.58 2 9.09 30.15 2.73 9.05 0.00 0.00 3 18.75 40.31 17.50 37.68 6.25 17.08 4 28.57 48.80 28.57 48.80 20.00 34.64 5 21.33 39.98 15.67 34.81 10.67 28.64 6 0.00 0.00 0.00 0.00 0.00 0.00 7 37.50 44.93 23.80 38.94 11.52 27.81 8 25.59 41.65 15.29 31.84 5.29 15.42 11 7.06 24.43 2.94 12.13 1.18 4.85 * School 9 removed due to data coding error and school 10 had no raising voice events.

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From page 89...

... Appendix E – Observational Classroom Study Report E-27 Table 40: Adjusted association between external TA and starting a teacher voice masking event, clustered by classroom within school. Adjusted Odds Ratio (95% Confidence Interval) External TA55 TA55 within 5 seconds prior to starting masking 1.00 (1.00, 1.00)

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From page 90...

... Appendix E – Observational Classroom Study Report E-28 Table 42: Associations of internal and external TA metrics with the number of teacher voice masking events observed in a session. No masking events in a session One masking event in a session Two masking events in a session Three or more masking events in a session RRR (95%CI)

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From page 91...

... Appendix E – Observational Classroom Study Report E-29 Table 44: Associations of internal and external TA metrics with the number of teacher voice raising events observed in a session. No voice raising events in a session One voice raising event in a session Two or more voice raising events in a session RRR (95%CI)

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From page 92...

... Appendix E – Observational Classroom Study Report E-30 Table 46: Mean and standard deviation (SD) of number of aircraft events observed per hour over a specified threshold when classroom sessions were being observed. Mean (SD)

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From page 93...

... Appendix E – Observational Classroom Study Report E-31 4.8. NA metrics and number of teacher voice raising events This section describes analyses comparing the number of aircraft noise events above set thresholds per hour when a classroom session was being observed, with the number of teacher voice raising events observed in a classroom session per hour. For analyses using the NA noise metrics, the teacher outcome of voice raising events had to be reformatted, as the NA noise metrics were calculated for one‐hour periods. Therefore, the teacher voice raising events were categorized as no events per hour, between 0 and less than one event per hour, and more than one event per hour. For example if in a 1 ½ hour classroom session only one masking event happened then masking per hour would be 1/1.5= 0.67 for this particular session and hence be placed in the between 0 and less than one event per hour group. Table 48 shows that 63% of the classroom sessions observed had no teacher voice raising events per hour; 14% of the classroom sessions had between 0 and less than one teacher voice raising event per hour; and 23% of the classroom sessions had more than one voice raising event per hour. Table 48: Number of teacher voice raising events observed per hour across the classroom sessions. Number of teacher voice masking events observed in the classroom session per hour. Number of sessions % of sessions 0 events per hour 83 63.4 0 < events per hour ≤ 1 18 13.7 More than 1 event per hour 30 22.9 Table 49 shows the association of the internal and external NA metrics with the number of voice raising events observed. These data are shown for one hour intervals in the observation sessions, as the NA metrics are calculated per hour. Table 49 shows that there were consistent significant associations between the internal NA metrics and teacher voice raising events. A one event increase in internal NA55, NA60, NA65, NA70, and NA75 was associated with a 11‐30% increase in the risk for observing 0 to 1 voice raising events, and a 11‐113% increase in the risk for observing more than one voice raising event. Internal NA metrics ranging from NA55 to NA70 were associated with a similar increase in the risk for more than one raising voice event, around a 9 to 15%, increase in risk, whereas NA75 and NA80 were associated with larger increases in risk (33% and 113%, respectively) . A one noise event increase in external NA55, NA60, NA65, NA70, NA75, and NA80 was associated with an 8‐20% increase in the risk for observing 0‐1 voice raising events. A one noise event increase in external NA55, NA60, NA65, and NA70 was associated with a 9‐10% increase in the risk for observing more than one voice raising event.

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From page 94...

... Appendix E – Observational Classroom Study Report E-32 Table 49: Association between internal NA metrics per hour and the number of teacher voice raising events per hour No Raising voice in the hour session 0 < to≤ 1 voice raising events per hour in a session More than 1 voice raising events per hour in a session RRR (95%CI)

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From page 95...

... Appendix E – Observational Classroom Study Report E-33 Table 50: Modelled annual LAeq 24 hours for each school School id Modelled annual LAeq 24 hours (dB) 1 65.5 2 67.4 3 50.5 4 65.6 5 61.9 6 43.7 7 57.2 8 45.7 9 46.4 10 48.4 11 42.6 5.2. Annual LAeq 24 hours and number of teaching voice masking events Table 51 shows the association between the annual average LAeq and the number of teacher voice masking events observed per hour in the classroom observation sessions. The table shows that for each 1dB increase in LAeq 24 hours the risk for observing one to two voice masking events increased by 8% and the risk for observing more than two voice masking events increased by 17%. The data are indicative of a dose‐response relationship between annual LAeq and the risk of voice masking events. We can estimate that a 10dB increase in annual LAeq 24 hours would be associated with an 80% increase in risk for one to two voice masking events (1.08*

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