See the FAQ: How_can_I_process_a_sequence_of_files?
The "dir()" version of the code is probably what you want. So do the loop once to scan the files, calling audioread, then get the length, then scan again to do the cropping. Make sure you save into a different folder so you don't permanently destroy your input sound files. In short:
filePattern = fullfile(inputFolder, '*.wav');
files = dir(filePattern)
minLength = inf;
for k = 1 : length(files)
thisFileName = fullfile(inputFolder, files(k).name);
[y, fs] = audioread(thisFileName);
if length(y) > minLength
maxLength = length(y);
end
end
% Now scan again, doing the cropping
for k = 1 : length(files)
thisFileName = fullfile(inputFolder, files(k).name);
[y, fs] = audioread(thisFileName);
y = y(1:minLength);
outputFileName = fullfile(outputFolder, files(k).name);
audiowrite(...........
end
etc. Or something like that. Of course you need to assign inputFolder and outputFolder to some actual folders on your drive.
