scope:

This Technical Report specifies a method for measuring the insertion loss of ear-muff type hearing protectors for quality inspection purposes. The method may also be used to investigate production spreads of performance as part of type approval or certification procedures and to investigate the change of performance with age. A measurement of application force is specified because the force affects acoustic performance. The method specified in this Technical Report is not intended to be used as the basic test for type approval puposes. Performance data obtained by the method are not to be quoted as representing the real-ear sound attenuation of an ear-muff, nor the protection provided by the ear-muff.