Hi, I am implementing : a] Bark scale to frequency and b] frequency to Bark scale equations. I have found an old posting from the auditory list to help with this. Would anyone have constructive criticism on the attatched scripts ? The execution of the following in octave plots the jpg (attatched). octave:1> f=1:20000; octave:2> plot( b2f( f2b(f) )) In my opinion it should be a straight line. Matt -- http://mffm.darktech.org WSOLA TimeScale Audio Mod : http://mffmtimescale.sourceforge.net/ FFTw C++ : http://mffmfftwrapper.sourceforge.net/ Vector Bass : http://mffmvectorbass.sourceforge.net/ Multimedia Time Code : http://mffmtimecode.sourceforge.net/
function f=b2f(z) %# returns f in Hz for bark scale value z %# from here http://www.auditory.org/postings/1995/34.html f=((exp(0.219*z)/352)+0.1).*z-0.032*exp(-0.15*(z-5).^2); f=f*1000; endfunction
function b_0=f2b(f) %# calculates the bark band location of f in Hz %# from here http://www.auditory.org/postings/1995/34.html b_0=13*atan(0.76*f/1000)+3.5*atan((f/1000).^2/56.25); %#Schroeder (1977) %# b_1 = 7*asinh(f/650); %# Traunm?ller (1990) %# b_2 = 26.81./(1+(1960./f)) - 0.53; %# Terhardt (1979) %# b_3 = 13.3*atan(0.75*f/1000); %# b_3= 12.82*atan(0.78*f/1000) + 0.17*(f/1000).^1.4; %# Zwicker & Terhardt (1980) %# f=f/1000; %# b_4=13*atan(0.76*f)+3.5*atan(f/7.5).^2; %# plot(b_1); hold on %# plot(b_2); plot(b_3); plot(b_4); hold off endfunction
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