the 90dB of noise masking isn't all sound energy. they're also ear plugs (on the less effective end of things) so 15-20dB of that 90 is from jamming them into t

the 90dB of noise masking isn't all sound energy. they're also ear plugs (on the less effective end of things) so 15-20dB of that 90 is from jamming them into the ear canal.