Long Term Average Spectrum of large batch of audio files I'm trying to obtain the overall LTAS of a large batch of audio (wav) files. To do this, I should obtain the LTAS of each file individually, then take the average value across all LTASs for each frequency. I also need the standard deviation for each frequency. I'm doing this in Matlab, but am rather a noob. Can anyone offer any pointers to help me write a Matlab script to do this? Thanks!
use "wavread()" to read the audio files 
use "pwelch()" to calculated the power spectrum of the songs
you do energy averagin over multiple songs.


Something like this (just a code sketch)

nx = 8192; % that's about 5 Hz @44.1 kHz
dd = dir('*.wav'); % all files in the current directory
nFiles = length(dd);
LTAS = zeros(nx/2+1,nFiles)
for i = 1:nFiles
  x = wavread(dd(i).name);
  LTAS(:,i) = pwelch(x,hanning(nx),nx/2);
end
LTASOverAllSongs = mean(LTAS,2);