hasdata returns a logical scalar indicating whether or not there is unread data in the datastore. You can use audioDatastore to read files sequentially until all data is read.

Specify the file path to the audio samples included with Audio Toolbox™.

folder = fullfile(matlabroot,'toolbox','audio','samples');

Create an audio datastore that points to the specified folder.

ADS = audioDatastore(folder);

While the datastore has unread data, read from the datastore.

while hasdata(ADS)
    data = read(ADS);
end