0 dB is the hearing threshold = 0,0002 microbar

Decibel:

a unit used to express the intensity of a sound wave, equal to 20 times the common logarithm of the ratio of the pressure produced by the sound wave to a reference pressure, usually 0.0002 microbar.

1928, coined from L. decibus "tenth," from decem "ten" + bel unit for measuring sound, after Alexander Graham Bell.

According to SOWPODS (the combination of Scrabble dictionaries used around the world) there are 3 words with the pattern MI-R--A-. That is, eight letter words with 1st letter M and 2nd letter I and 4th letter R and 7th letter A. In alphabetical order, they are:

microbar

microcap

microcar

According to SOWPODS (the combination of Scrabble dictionaries used around the world) there are 3 words with the pattern -I---BAR. That is, eight letter words with 2nd letter I and 6th letter B and 7th letter A and 8th letter R. In alphabetical order, they are:

cinnabar

microbar

millibar

According to SOWPODS (the combination of Scrabble dictionaries used around the world) there are 8 words with the pattern -I-R-B--. That is, eight letter words with 2nd letter I and 4th letter R and 6th letter B. In alphabetical order, they are:

disrobed

disrober

disrobes

microbar

microbes

microbic

microbus

titrable