Table 4.

Classroom details and acoustic measures

School	Classroom	Grade level/s	Condition sequence	No of participants	Mean age (years)	Mean unoccupied teacher voice (dBA)			Mean occupied classroom noise level (dBC)
						Without SFA	With SFA	Gain from SFA	Without SFA	With SFA
1	1A	3	On/Off/On	7	8.81	61.5	66.05	4.55	74.2	74.0
1	1B	4	Off/On/Off	3	9.92	65.27	70.57	5.30	70.3	70.4
1	1C	3	Off/On/Off	9	8.77	62.07	64.92	2.85	66.7	67.1
1	1D	4	On/Off/On	5	9.88	61.30	65.9	4.60	71.3	71.1
2	2A	3/4	On/Off/On	11	10.26	52.78	55.95	3.17	70.6	65.2
2	2B	3/4	Off/On/Off	9	10.68	51.58	55.42	3.84	67.0	69.4
2	2C	3/4	On/Off/On	5	9.74	53.47	57.88	4.41	65.0	63.0
2	2D	3/4	Off/On/Off	1	10.66	52.87	56.97	4.10	67.8	69.4
3	3A	3/4	On/Off/On	12	10.30	58.3	61.6	3.30	68.6	58.0
3	3B	3/4	Off/On/Off	12	10.43	53.55	56.72	3.17	64.3	68.2
4	4A	3	On/Off/On	10	9.29	55.2	65.52	10.32	76.0	60.7
4	4B	4	Off/On/Off	4	10.13	57.63	63.43	5.80	60.1	72.8
5	5A	3	Off/On/Off	8	9.62	57.05	62.33	5.28	60.0	62.4
5	5B	4	On/Off/On	8	10.33	57.37	65.47	8.10	66.6	59.0
6	6A	3	Off/On/Off	4	9.39	62.12	67.67	5.55	62.8	75.6
6	6B	3	On/Off/On	6	9.33	51.78	59.33	7.55	75.2	64.3
6	6C	3	On/Off/On	7	9.32	63.18	65.67	2.49	74.0	61.5
6	6D	3	On/Off/On	3	9.35	56.08	68.72	12.64	70.2	64.7
6	6E	4	On/Off/On	4	9.82	56.08	63.95	7.87	72.3	69.5
6	6F	4	Off/On/Off	9	9.89	54.87	64.5	9.63	69.3	71.6
6	6G	4	Off/On/Off	6	9.99	60.28	66.87	6.59	66.5	69.5
6	6H	4	Off/On/Off	7	9.77	62.65	68.32	5.67	70.1	*
6	6I	4	On/Off/On	2	9.50	58.92	68.32	9.40	*	66.5
All participants				152	9.36	57.65	63.57	5.92	68.59	67.00

^*Data not captured due to the class being off-site at the time of recording.