Speech

 Evolution of the brain differentiated humans from animals, as among other things it allowed humans to master a very efficient form of communication, speech.
 
Speech greatly facilitated the transmission of information and knowledge to further generations.
 
Speech placed humans at the top of the food chain, and facilitated human colonization of the entire planet.

        Radio

 The radio receives electromagnetic waves from the air that are sent by a radio transmitter.
 
Electromagnetic waves are a combination of electrical and magnetic fields that overlap.
The radio converts these electromagnetic waves, called a signal, into sounds that humans can hear.
 
Radios are a part of everyday life.
Not only are they used to play music or as alarms in the morning, they are also used in cordless phones, cell phones, baby monitors, garage door openers, toys, satellites, and radar.
Radios also play an important role in communications for police, fire, industry, and the military.
 
Nikola Tesla and other scientists and inventors showed the usefulness of radiotelegraphy, wireless telegraphy, or radio, beginning in the 1890s.
 
In 1943, the Supreme Court of the United States credited Nikola Tesla as being the inventor of the radio.

    Communication

 Tell me and I'll forget. Show me and I'll remember. Involve me and I'll understand.
 
The greatest problem in communication is the illusion that it has been accomplished.
 
The most important thing in communication is to hear what isn't being said.
 
You are not only responsible for what you say, but also for what you do not say.
 
Good communication is as stimulating as black coffee, and just as hard to sleep after.