k0 2*pi*freq/c0 "Wave number"
alpha_all if(isnan(acpr.imp1.alpha_n),0,acpr.imp1.alpha_n)+if(isnan(acpr.imp2.alpha_n),0,acpr.imp2.alpha_n)+if(isnan(acpr.imp3.alpha_n),0,acpr.imp3.alpha_n)+if(isnan(acpr.imp4.alpha_n),0,acpr.imp4.alpha_n)+if(isnan(acpr.imp5.alpha_n),0,acpr.imp5.alpha_n)+if(isnan(acpr.imp6.alpha_n),0,acpr.imp6.alpha_n) "Absorption coefficent of surfaces"
Zn_seat acpr.rho*acpr.c*(realZ_seat(freq)+i*imagZ_seat(freq)) "Specific impedance of leather seats"