Appendix I — PSA and Liveliness

Percentage

                                                                                         kn
a) Solid line - Speech level coefficient    kr
                                           b) Reverberation Time coefficient (kr)        c) Noise level coefficient (kn).
   (ki). Dotted line - PSA vs. speech                                                       Solid line- speaker and listener
   level                                                                                    in noise. Dotted line- only
                                                                                            listener in noise
             Figure 8.I.1 Coefficients for Percentage Syllable Articulation (PSA)
   (Source: Knudsen, V. O. 1932. Architectural Acoustics, John Wiley & Sons Inc., New York)

Figure 8.I.2 Liveliness of a Room as a Function of its Volume and Total Absorption (Source: Stein, B. et al. 2006. Mechanical and Electrical Equipment for Buildings. John Willey & Sons, New Jersey) Note: The room proportions chosen as Length : Width : Height = 2H : 1.5H : H; average of the three extreme points of the recommended room proportion triangle in Fig. I.2. For these proportions, S = 6.25 V2/3 and thus A = S  = 6.25 V2/3.