00314nam a2200097Ia 4500008004100000082001500041100001900056245010200075264003100177300000800208200526s9999||||xx |||||||||||||| ||und||  a617.8  EWE  aEwertsen, H.W. 0aOperation Helen: First Preliminary Report: Auditive, Visual and Audio Visual Perception of Speech  bState Hearing Centrec1973  a68p