Advances in generator noise mitigation: A systematic review and meta-analysis of structural design, acoustic materials, and active noise control systems

Generator installations are important sources of environmental noise in and around buildings, often exceeding acceptable levels for residential and occupational settings. This systematic review and meta-analysis synthesized quantitative evidence on noise-control strategies for generator systems. Searches of 11 scientific databases to December 2024 identified experimental and field studies reporting measurable noise-reduction outcomes. Twenty-four studies met the inclusion criteria and were pooled using random-effects models. Across all methods—including structural modifications, multilayer acoustic enclosures, silencers, passive materials, vibration isolation, and active or hybrid active–passive noise control—the overall mean reduction was 14.66 dB (95% CI: 12.49–16.83 dB), with substantial heterogeneity. Subgroup analyses indicated superior performance for high-efficiency silencers and well-designed enclosures compared with simple barriers or single-layer treatments. These findings provide consolidated evidence to inform the design and optimization of generator noise-control solutions within the built environment.