Soldiers and supporting engineers are frequently exposed to high low-frequency (<500Hz) cabin noise in military vehicles. Despite\nthe use of commercial hearing protection devices, the risk of auditory damage is still imminent because the devices may not be\noptimally customised for such applications. This study considers flax fibre-reinforced polypropylene (Flax-PP) as an alternative to\nthe material selection for the ear cups of commercial earmuffs, which are typically made of acrylonitrile butadiene styrene (ABS).\nDifferent weaving configurations (woven and nonwoven) and various noise environments (pink noise, cabin booming noise, and\nfiring noise) were considered to investigate the feasibility of the proposed composite earmuffs for low-frequency noise reduction.\nThe remaining assembly components of the earmuff were kept consistent with those of a commercial earmuff, which served as\na benchmark for results comparison. In contrast to the commercial earmuff, the composite earmuffs were shown to be better\nin mitigating low-frequency noise by up to 16.6 dB, while compromising midfrequency acoustical performance. Consequently,\nthe proposed composite earmuffs may be an alternative for low-frequency noise reduction in vehicle cabins, at airports, and at\nconstruction sites involving heavy machineries.
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