Most histories of Marilyn’s career ignore her classes at the Actors Lab and her performances at the playhouse. Her achievements there show that she had stage experience and capacity to sustain a long performance as well as a facility for remembering lines and the power to project her voice to the back of a theater. People who knew her personally were aware of the breathy voice as a gimmick; Jim Dougherty, for instance, comments in his memoir upon this affectation. The whispery voice was Marilyn’s creation, along with several other trademarks that combined to produce her public persona.
-My Sister Marilyn by Berniece Baker Miracle