The error is being generated because the Sound Device has not been added
or properly configured for this experiment.  In any experiment in which
you wish to present sound, the Sound Device on the Experiment Object of
your E-Prime experiment must be added to the Experiment Object.  It must
also be configured for the same audio format as your sound files.
Please open the Experiment Object (in the Structure window of your
experiment), click on the Devices tab, and select the Sound Device
(Select "Add" and add the Sound Device first, if you have not already
done so).  

If you click Edit, you will be able to see the current configuration and
make changes to match the audio formats of your WAV file(s), if
necessary. The formats of your WAV files must match each other AND the
format of the Sound Device. Please check the audio formats of your WAV
files.  You can do this by opening the files in Windows Sound Recorder
and, under the File menu, selecting Properties.  You should choose a
format that is directly supported by E-Prime (8 bit or 16 bit, 22050Hz
or 44100Hz, stereo or mono), and all of your sound files that will be
used in this experiment should be saved in that format.

I hope this information is helpful.

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Psychology Software Tools, Inc.
2050 Ardmore Blvd.
Pittsburgh, PA 15221-4610
USA
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Visit our Web Site for the latest info:
http://www.pstnet.com
E-mail: info@pstnet.com
Voice (412) 271-5040