V_IMPORTSII calculates the SII importance function per Hz or per Bark Q=(F,M)
Inputs:
f(n) Frequencies to which to calculate importance in Hz
or Bark according to 'b' flag.
m Mode string with some of the following flags:
'b' Frequencies given in Bark rather than Hz
'c' Calculate cumulative importance for f<f(i)
'd' Calculate importance of n-1 bands: band i is f(i) to f(i+1)
'h' Calculate importance per Hz or per Bark (accoring to 'b' flag)
Outputs:
q(n) or q(n-1) gives the importance at each of the f(i) or else,
if the 'd' flag is specified, in the band from f(i) to f(i+1).0001 function q=v_importsii(f,m) 0002 %V_IMPORTSII calculates the SII importance function per Hz or per Bark Q=(F,M) 0003 % Inputs: 0004 % f(n) Frequencies to which to calculate importance in Hz 0005 % or Bark according to 'b' flag. 0006 % m Mode string with some of the following flags: 0007 % 'b' Frequencies given in Bark rather than Hz 0008 % 'c' Calculate cumulative importance for f<f(i) 0009 % 'd' Calculate importance of n-1 bands: band i is f(i) to f(i+1) 0010 % 'h' Calculate importance per Hz or per Bark (accoring to 'b' flag) 0011 % Outputs: 0012 % q(n) or q(n-1) gives the importance at each of the f(i) or else, 0013 % if the 'd' flag is specified, in the band from f(i) to f(i+1). 0014 0015 % The importance function is based on the piecewise linear function 0016 % defined in Fig 3 of [2]. This is integrated to give the cumulative 0017 % importance function. It is modified slightly from Fig 3 so that the 0018 % constant portion extends from 4 to 18 Bark (critical bands 5 to 18). 0019 % we then fit a linear portion at either end to force the correct integral 0020 % and ensure continuity of the importance at 4 and 18. The importance 0021 % function is zero outside the range [1.286 21.948] bark or [130.1 9361] 0022 % Hz. 0023 % 0024 % References: 0025 % [1] Methods for the calculation of the speech intelligibility index. 0026 % ANSI Standard S3.5-1997 (R2007), American National Standards Institute, 1997. 0027 % [2] C. V. Pavlovic. Derivation of primary parameters and procedures for use in 0028 % speech intelligibility predictions. J. Acoust Soc Amer, 82: 413�422, 1987. 0029 0030 % Copyright (C) Mike Brookes 2006 0031 % Version: $Id: v_importsii.m 10865 2018-09-21 17:22:45Z dmb $ 0032 % 0033 % VOICEBOX is a MATLAB toolbox for speech processing. 0034 % Home page: http://www.ee.ic.ac.uk/hp/staff/dmb/voicebox/voicebox.html 0035 % 0036 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% 0037 % This program is free software; you can redistribute it and/or modify 0038 % it under the terms of the GNU General Public License as published by 0039 % the Free Software Foundation; either version 2 of the License, or 0040 % (at your option) any later version. 0041 % 0042 % This program is distributed in the hope that it will be useful, 0043 % but WITHOUT ANY WARRANTY; without even the implied warranty of 0044 % MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 0045 % GNU General Public License for more details. 0046 % 0047 % You can obtain a copy of the GNU General Public License from 0048 % http://www.gnu.org/copyleft/gpl.html or by writing to 0049 % Free Software Foundation, Inc.,675 Mass Ave, Cambridge, MA 02139, USA. 0050 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% 0051 0052 persistent mi ci ai bi xi0 xi1 0053 if isempty(mi) 0054 % cumulative importance function = mi*b+c+ai*(b<4)*(b-4)^2-bi*(b>18)*(b-18)^2 0055 % for x in (xi0,xi1) 0056 ci4=0.0783; 0057 ci18=0.8861; 0058 mi=(ci18-ci4)/14; 0059 ci=ci4-4*mi; 0060 ai=mi^2/(4*(4*mi+ci)); 0061 bi=mi^2/(4*(1-18*mi-ci)); 0062 xi0=4-mi/(2*ai); 0063 xi1=18+mi/(2*bi); 0064 end 0065 if nargin<2 0066 m=' '; 0067 end 0068 if any(m=='b') 0069 b=f; 0070 else 0071 [b,d]=v_frq2bark(f); 0072 end 0073 if any(m=='c') || any(m=='d') 0074 q=mi*b+ci+ai*(b<4).*(b-4).^2-bi*(b>18).*(b-18).^2; 0075 q(b<xi0)=0; 0076 q(b>xi1)=1; 0077 if any(m=='d') 0078 q=q(2:end)-q(1:end-1); 0079 end 0080 else 0081 q=mi+ai*(b<4).*(b-4)-bi*(b>18).*(b-18); 0082 q(b<xi0)=0; 0083 q(b>xi1)=0; 0084 if ~any(m=='b') 0085 q=q./d; 0086 end 0087 end 0088 if ~nargout 0089 if any(m=='d') 0090 ix=(1:2*length(q))/2; 0091 plot(f(1+floor(ix)),q(ceil(ix))); 0092 else 0093 plot(f,q); 0094 end 0095 if any(m=='b') 0096 xlabel('Frequency (Bark)'); 0097 else 0098 xlabel('Frequency (Hz)'); 0099 end 0100 ylabel('Importance'); 0101 if any(m=='c') 0102 title('SII Cumulative Importance'); 0103 elseif any(m=='d') 0104 title('SII Band Importance'); 0105 else 0106 title('SII Importance Function'); 0107 end 0108 end 0109