Abstract
21^<st> century is said to be the age of knowledge creation. 20^<th> century has been an age of product realization. What are their differences? The main difference is that in an age of product realization, the value of products was determined by market. But the value of knowledge is not, It is determined by communication between the knowledge creator and its potential buyer, because the value of knowledge varies from customer to customer, depending upon what experience he or she had in his or her life. Thus, the knowledge cannot be sold unless the knowledge creator communicates with its potential buyer person to person to estimate how a person looks at life.. But the present communication technology, although very much advanced, does not provide enough capabilities for listening to understand on what a potential buyer set a high value. The current technology focuses its primary attention to convey exactly what a speaker would like to tell. Thus, listen technology has to be developed in addition to the present framework of speak technology.