This page shows one of the basic principles of multi-leaf wall systems, showing "double leaf" vs "triple leaf" vs "quadruple leaf" walls, and their sound transmission loss (isolation) both by STC and by individual frequency bands. It is extracted here from the original documents.

It originally appeared as Figure 2 in:

  Avoiding Flanking Noise Transmission
  by V. Young-Benidickson
  Originally published in "RAIC Update" 16(2), 1992, p. 7-8             
and the multi frequency wall transmission loss data is from:

  IR761 Gypsum Board Walls: Transmission Loss Data
  by R.E. Halliwell, T.R.T. Nightingale, A.C.C. Warnock, J.A. Birta
  Internal Report IRC-IR-761, March 1998

V. Young-Benidickson is a freelance writer in Ottawa.
The IRC contact is Dr. A.C.C. Warnock (Senior Research Officer, Acoustics Section, Institute for Research in Construction, National Research Council Canada)
IRC has been asked for approval of this page. The original documents can be found by clicking on the links above.