Low-Frequency Noise Reduction by Earmuffs with Flax Fibre-Reinforced Polypropylene Ear Cups

Table 1

Density of the respective flax fabrics and the polypropylene film.

Fabric/film	Fabric density [g/m^2]
Nonwoven mat	300
twill weave mat	400
hopsack weave mat	500
Polypropylene film	90