Purpose

The purpose of the research is to work out a method for determining the sound insulation of acoustic enclosures for industrial sources emitting noise in the frequency range of 10–40 kHz and apply the method to measure the sound insulation of acoustic enclosures build of different materials.

Methods

The method is developed by appropriate adaptation of techniques applicable currently for sound frequencies of up to 10 kHz. The sound insulation of example enclosures is determined with the use of this newly developed method.

Results

The research results indicate that enclosures (made of polycarbonate, plexiglass, sheet aluminium, sheet steel, plywood, and composite materials) enable reducing the sound pressure level in the environment for the frequency of 10 kHz by 19–25 dB with the reduction increasing to 40–48 dB for the frequency of 40 Hz. The sound insulation of acoustic enclosures with a sound-absorbing material inside reaches about 38 dB for the frequency of 10 kHz and about 63 dB for the frequency of 40 kHz.

Conclusion

Some pieces of equipment installed in the work environment are sources of noise emitted in the 10–40 kHz frequency range with the intensity which can be high enough to be harmful to humans. The most effective technical reduction of the associated risks are acoustic enclosures for such noise sources. The sound pressure level reduction obtained after provision of an enclosure depends on its design (shape, size, material, and thickness of walls) and the noise source frequency spectrum. Realistically available noise reduction values may exceed 60 dB.

中文翻译：

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减少噪音对人类环境的有害影响。10-40 kHz频率范围内工业骨架外壳的隔音

目的

本研究的目的是针对10-40 kHz频率范围内的工业噪声源，制定一种确定隔音罩隔音的方法，并将该方法应用于不同材料制造的隔音罩的隔音测量。

方法

该方法是通过适当调整当前适用于高达 10 kHz 声频的技术而开发的。使用这种新开发的方法来确定示例外壳的隔音效果。

结果

研究结果表明，外壳（由聚碳酸酯、有机玻璃、铝板、钢板、胶合板和复合材料制成）能够将 10 kHz 频率的环境中的声压级降低 19-25 dB，降低幅度增加到40 Hz 频率为 40–48 dB。内部装有吸音材料的隔音罩在10 kHz的频率下达到约38 dB，在40 kHz的频率下达到约63 dB。

结论

安装在工作环境中的某些设备是 10-40 kHz 频率范围内发出的噪声源，其强度可能高到足以对人体有害。最有效地降低相关风险的技术是为此类噪声源设置隔音罩。提供外壳后获得的声压级降低取决于其设计（形状、尺寸、材料和壁厚）和噪声源频谱。实际可用的降噪值可能超过 60 dB。