Help needed with DECTALK EXPRESS

[cris]

Dear listers,
I have just purchased a dectalk express to use with linux.  However, the
sound is barely audible.  It can not be battery problem because even with
the external power on, the sound is still low.  Is there a way of resetting
this box to produce louder sound?  Even when I turn the volume to Max,
sometimes I miss words if there was a fan going on in the room.  I am sure
that I have not lost my hearing yet.  Do I need a software to reset the
Parameters?  Any ideas would be appreciated.
Cheers,
Cris Ali