Comparison 8. HLPP with noise level indicator vs no noise level indicator.

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
1 Change in noise levels at 2 months' follow‐up	1	132	Mean Difference (IV, Random, 95% CI)	0.32 [‐2.44, 3.08]
1.1 Extensive information plus NLI vs information only	1	64	Mean Difference (IV, Random, 95% CI)	‐0.40 [‐4.37, 3.57]
1.2 Information plus NLI vs Information only	1	68	Mean Difference (IV, Random, 95% CI)	1.0 [‐2.84, 4.84]
2 Change in noise levels at 4 months' follow‐up	1	132	Mean Difference (IV, Fixed, 95% CI)	‐0.14 [‐2.66, 2.38]
2.1 Extensive information plus NLI vs information only	1	64	Mean Difference (IV, Fixed, 95% CI)	‐0.30 [‐3.95, 3.35]
2.2 Information plus NLI vs information only	1	68	Mean Difference (IV, Fixed, 95% CI)	0.0 [‐3.48, 3.48]