If you want to take it up a notch, my mother with an auditory deficit (http://specialed.about.com/cs/iep/a/auditorydeficit.htm http://specialed.about.com/cs/iep

If you want to take it up a notch, my mother with an auditory deficit (http://specialed.about.com/cs/iep/a/auditorydeficit.htm http://specialed.about.com/cs/iep/a/auditorydeficit.htm) hear's the same sound despite changes in phenome being shown.