Dawn@4: function [ASBP] = AudioSpectralBandPower(raw, fs, noOfFrames, frameLength)
Dawn@4: % this file normalises the frequency spectrum and calculates the spectral
Dawn@4: % power in frequency band 100 - 1000 Hz and in the top 
Dawn@4: x = buffer( raw, frameLength );
Dawn@4: myColor = 'rx';
Dawn@4: 
Dawn@4: hiEdgeSamples = getMaxFreq; % the highest fundamental
Dawn@4: loEdgeSamples = getMinFreq; % the lowest fundamental
Dawn@4: 
Dawn@4: hiFreqBin = ceil(((frameLength/2)/(fs/2))*hiEdgeSamples);
Dawn@4: loFreqBin = floor(((frameLength/2)/(fs/2))*loEdgeSamples);
Dawn@4: 
Dawn@4: bandWidth = hiFreqBin - loFreqBin;
Dawn@4: 
Dawn@4: for n = 1:noOfFrames
Dawn@4:     spectrum = abs( fft( x(:,n) ));
Dawn@4:     spectrum = spectrum( 1 : frameLength/2 );
Dawn@4:     % normalise
Dawn@4: %     spectrum = spectrum/max(spectrum);
Dawn@4:     % fundamental frequency band
Dawn@4:     lBand = ( loFreqBin : hiFreqBin );
Dawn@4:     hBand = ( frameLength/2 - ( bandWidth ) : frameLength/2 );
Dawn@4:     lBandPower = sum( spectrum( lBand ));
Dawn@4:     hBandPower = sum( spectrum( hBand ));
Dawn@4: %     gm(n) = nthroot( prod( spectrum ), frameLength );
Dawn@4: %     am(n) = sum( spectrum )/frameLength;
Dawn@4:     ASBP(n) = lBandPower/hBandPower;
Dawn@4: %     subplot(421); plot( x(:,n) );
Dawn@4: %     subplot(422); plot( spectrum ); hold on; 
Dawn@4: %     plot( loFreqBin : hiFreqBin, spectrum( lBand ), 'r' );
Dawn@4: %     plot( hBand, spectrum( hBand ), 'r' ); hold off
Dawn@4: %     
Dawn@4: % %     look at the frame with reference to the surrounding 10 frames
Dawn@4: %     if( n>5 )
Dawn@4: %         startPlot = (n-5)*frameLength+1;
Dawn@4: %         endPlot = (n+5)*frameLength;
Dawn@4: %     else
Dawn@4: %         startPlot = 1;
Dawn@4: %         endPlot = 10*frameLength;
Dawn@4: %     end
Dawn@4: %     subplot(412); plot( raw( startPlot : endPlot ) ); hold on; 
Dawn@4: %     plot( ((n-1)*frameLength+1) - startPlot : (n*frameLength) - startPlot, x(:,n), 'r' ); hold off;
Dawn@4: %     
Dawn@4: %     subplot(425); plot( n, lBandPower, myColor ); hold on;%plot( n, gm(n), myColor ); hold on;
Dawn@4: %     subplot(426); plot( n, hBandPower, myColor ); hold on;%plot( n, am(n), myColor ); hold on;
Dawn@4: %     subplot(414); plot( n, lBandPower / hBandPower, myColor ); hold on;%plot( n, ASF(n), myColor ); hold on;
Dawn@4: % end
Dawn@4: end
Dawn@4: 
Dawn@4: 
Dawn@4: 
Dawn@4: 
Dawn@4: