In every society, humans have developed spoken and written language as a means of sharing messages and meanings. The most common form of daily communication is interpersonal-that is, face-to-face, at the same time and in the same place.
Communication may also occur in small groups, such as families, clubs, religious groups, friendship groups, or work groups.
A special case of small-group interaction occurs in organizations where there is work to do or a task for the group to perform. Or several small groups may need to interact among each other within a single organization. In these cases, the groups must communicate well, both among themselves and with other groups, so that their members can perform their work effectively and make good decisions.
Interpersonal communication occurs with larger groups as well, such as when a speaker gives a talk to a large crowd （a teacher lecturing to a large class）. However, the audience can respond in only limited ways （such as with applause, nodding, whistles, boos, or silence）. The speaker usually wants to be persuasive or informative, so the words chosen and the style of delivery or performance are very important.
Radio（收音机）: Most large cities and many small towns have a number of local radio stations, on both the AM and the FM frequencies. Some frequencies are dedicated to citizens-band （CB） radio, which long-distance truck drivers use to check on road conditions, report problems, or just to chat. Special frequencies are devoted to emergency use, such as police, fire, or emergency medical dispatching, or to aviation radio.
Television（电视）:There is no doubt that television has been one of the most important communication technologies in history. Televisions are switched on an average of seven hours a day in households. Debates continue about the medium's effects on children, culture, education, politics, and community life.
Critics say that television feeds a constant stream of simplified ideas and sensationalistic images, that it has a negative effect on political campaigns and voting patterns, that it destroys local cultures in favor of a bland national culture, and that it has encouraged the growth of an uncritical and passive audience.
Defenders say that television provides a great deal of high-quality educational and cultural programming, and that it is the major source of national and international news and information for most citizens.
As the Canadian writer Marshall McLuhan pointed out, perhaps nothing has been more responsible for creating the global village-the sense that we can see and hear events anywhere in the world as they happen, and so can feel more connected to other places.
Computer（电脑）:Since the 1970s personal computers have transformed American business, education, and entertainment. People can use computers to design graphics and full-motion video, compose music, send electronic mail, make airline or hotel reservations, or search the Library of Congress over the World Wide Web. They can play games and even visit electronic rooms or parties to talk to other people.
Computers are used in all aspects of business and education. Self-instructional computer programs help people learn new information or skills. Some programs are simulations, which imitate tasks that require the learner to perform in certain ways, and give the learner feedback about that performance.
Communication and Culture Change（通讯与文化演变）
Since the time of writing, communication technologies have had a major influence on society. Most observers agree that communication media and technologies have contributed to a society that is changing very rapidly.
New communication and information technologies have enabled many organizations and people to collect, organize, and sell information about other people and organizations, both quickly and cheaply. The easy availability of personal information makes banking, education, health care, and sales much more convenient for both consumers and sellers. Scanners in the supermarket rapidly and accurately record every item that passes over them, making grocery checkouts faster and error free.
The negative side to all this shared information is that there is little control over who sees or uses this personal information. Many people worry that having so much of their personal information available to so many others may hurt their privacy.
Another concern among researchers studying changes in society is the growing gap between the information rich （people with easy access to information） and the information poor （people with less access to information）.