that means that if you are listening at say 90 dB, the frequency response would be down to 37hz up to 22 khz, with a variation of + or - 3 dB (so between 87 and 93).

the response would be down to 27 hz and up to 22 khz between 83 and 93 dB

correct me if i am wrong, but i think this is right.