http://4lifeshaperite.com/rumbles/Conversations_with_Terri.html <= click on video and if needed, open with windows media player.
Without passing judgment, inasmuch as no 'base-line for vocalizations in this relationship' is as far as one knows afforded, here is a rather informationally striking video for which a link is circulating on the Net.
Addendum: For those concerned with human rights and human "being", what 'metrics' are there for judging the rewards among family members for any kind of feedback.
Best wishes, LDMF.
Linda D. Misek-Falkoff, Ph.D., J.D..
[affiliations on request].