Abstract:

Objective To explore in depth the generation mechanisms of multi-source noise in industrial production of automobile casting industry and corresponding noise reduction measures，and to evaluate the actual effectiveness of these interventions. Methods From 2020 to 2024，a field survey was conducted to investigate the basic situation and physical characteristics of different noise sources such as blowing，impact，collision，and vibration in the production process of automotive engines. The 8-hour equivalent continuous A-weighted sound pressure levels（L_{EX，8 h}） before and after noise control were measured and compared. Results A total of 36 individuals were enrolled in the study，targeted noise reduction measures were implemented for major noise sources such as blowing，hammering，and impact during casting processes，including low-pressure casting，low-pressure post-treatment，riser cutting，high-pressure deburring，high-pressure mold grinding，and high-pressure heat treatment. These interventions effectively reduced workers' noise exposure levels across different workstations. Compared with pre-intervention levels，the average reductions in L_{EX，8 h} at various workstations were （2.98±0.92），（19.42±0.66），（3.12±0.73），（4.67±0.49），（15.23±0.80），（12.00±0.87），（12.23±0.29），（5.02±0.75），（8.48±0.87） and （19.37±1.00）dB（A），respectively，with statistically significant differences（all P<0.05）. Furthermore，the occupational hazard classification of noise exposure decreased from grade Ⅲ-Ⅱ to grade I-0，significantly reducing the risk of noise exposure. Conclusion The implementation of multidimensional noise reduction technology can significantly reduce the exposure level of multi-source noise in the automotive casting industry，providing effective and scalable practical basis for noise control and occupational health management in similar manufacturing enterprises.

Key words: Noise, Noise reduction measures, Technological retrofit, Automobile manufacturing