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 interpersonalthat 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.
