The whole societal forces have seen a shift as a result of development in the area of communications. Different theories have also been put forward with respect to communications and as the time passed by theories evolved to cover new aspects and in recent times they now expand to media and its role in the whole process of communication.
Different theoretical models were put forward and the earliest model was a simple sender-channel-message-receiver model also known as transmission model. Most communication textbooks, including public speaking, begin with the transmission model of communication. Even today, it remains a valuable introductory model. This particular model was a straight chain and was not in the form of loop. So later, modifications added the concept of feedback, leading to a loop. Further developments in the theoretical models added dimensions to the role of receivers adding that receivers normally selectively perceive, interpret and retain messages.
Shannon and Weaver put forward their theories in 1949 and their model was considered very important in further developments. Again in their model communication was considered as a linear, one-way process but they also made a difference between source and transmitter, and receiver and destination. So instead of single function they noted that there are two functions at the transmitting end and two at the receiving end. Criticism hurled at the model presented by Shannon and Weaver was the ignorance of the fact that communication process is often endless while they suggested a definite start and finish to the communication process.
Decade of 50s brought in its wake further advancements for model-building, as fields of sociology and psychology developed. USA was the first country where the science of communication developed. Gerbner was among few who recognized the transactional nature of much communication that is the "intersubjectivity of communication". Additions to the earlier single chain or transactional communication model changed and experts started considering communication a matter of negotiation and cannot be predicted in advance. Later on developments of mass media, press, films and radio and political changes further accelerated mass communication research. Hence the focus shifted from communication to mass communication.
As mass communication became important, different new models began to refer specifically to mass communication. Westley and Maclean were among earlier experts who put forward their views emphasizing the significance of audience demand rather than just the communicator's purpose. The decades of 1960s and 1970s saw the concentration moving away from the effects of the mass media on opinions, behavior and attitudes, and began to converge on the long-term and socializing impact of the mass media. Some were of the opinion that the audiences in this whole media game are active that is they can adopt or reject the guidelines offered by the mass media. However, another group considered audiences the victims of the media resulting in a suspicion of the mass media that continued through the 1970s and 1980s, particularly in relation to news selection and presentation. With further changes in the communication arena the boundaries separating mass communication