Low-frequency attenuation depends critically on proper seal and construction

Evidence

It is hard to achieve good attenuation in the low frequencies unless the protector is very well sealed and of appropriate construction. Thus, the correct use of the hearing protectors is also important. Otherwise, the attenuation performance may be significantly worsened. — Ville Pulkki, Matti Karjalainen, Communication Acoustics- An…, 2703

Categorization

• XREF: connects to: Ground impedance, not foliage, governs low-band attenuation by vegetation. — Donald Aylor, Noise Reduction by Vegetation and Ground, 2