I have heard the phrase "Toothbrush" used to describe audio files that ride at "0" db. Viewing the wave file it looks like a side view of a tooth brush.
Phil Spector's "Do D00 Ron Ron" by the Crystals was mastered with Spectors "Wall of Sound" using dense layers of effects and "Toothbrush" "0" db levels.
If memory serves me right Spector came up with that technique (technique ?)
Google "Wall of sound" and youll find more info.
d nelson ward