nPerceptible vibration (RV): The sound level in the octave bands between 16 Hz and 63 Hz falls in the shaded regions (A and B). These regions indicate sound-pressure levels at which walls and ceilings can vibrate perceptibly—rattling cabinet doors, pictures, ceiling fixtures, and other furnishings in contact with them.
Region A: High probability that noise-induced vibration levels in lightweight wall and ceiling constructions will be felt. Anticipate audible rattles in light fixtures, doors, windows, and so on.
Region B: Noise-induced vibration levels in lightweight wall and ceiling constructions may be felt. Slight possibility of rattles in light fixtures, doors, windows, and so on.
The RC rating for the sound is the numerical SIL value calculated in Step Two and the letter descriptor determined in Step Five.
