impact sound pressure level

10.55  impact sound pressure level. In a specified frequency band, the average sound pressure level produced by the operation of the standard tapping machine on a floor-ceiling assembly as measured in a room below or near the room or space containing the tapping machine, averaged over each of the specified tapping machine positions. Unit, decibel (dB), abbreviation, ISPL (ASTM) or L_i.(ISO 10140-3).