The following chart is, however, for the dBA values no accurate knowledge − it's more a guess. "Conversion" of "sones to dBA" Conversion between sones and phons − but only a really rough "guess" for dBA values sones phons dBA sones phons dBA 0.1 17.9 20.5 1.8 48.5 34.8 0.2 22.8...