公开(公告)号：EP0129208A3

公开(公告)日：1986-07-23

申请号：EP84106789

申请日：1984-06-14

申请人： International Standard Electric Corporation

发明人： Gorman, Patrick Roland ,  Stottlemyer, William Otho

IPC分类号： H04M09/10 ,  H04M03/42

CPC分类号： H04M1/6033 ,  H04M9/10

摘要： A handsfree or loudspeaking telephone circuit employing loudest speaker comparison for controlling the direction of transmission of speech signals. The circuit employs the speech network for the handset to provide gain and hybrid functions. The circuit contains logic for controlling the switching between handset operation, handsfree operation and call announcing operation.