Investigation on enhancement of noise reduction of partially open windows and balconies through mock-up test

Application of Acoustic Windows and Acoustic Balconies is a recent trend in Hong Kong to mitigate road traffic noise impact. In severe situations, enhancement is needed for the mitigation measures to provide additional improvement in acoustic performance. The performances of several common enhancements including micro-perforated absorber panels, perforated absorption panels, and balcony sidewalls are investigated through 1:1 mock-up test. The mock-up test aimed to mimic the actual situation, by referencing the spatial relationship between line sources and receivers. International standards are followed in the mock-up test, including ISO 16283-3: 2016 for microphone setting-out and BS EN 1793-3 for normalized traffic noise spectrum. Based on the mock-up test results, the research revealed that the enhancements' performance changes with line source orientation and suggested the optimum usage of enhancements.