The telephone was invented on March 10, 1876 by Alexander Graham Bell. Despite the fact he is the one coined with making the phone, there were others who were doing the same research. Only a few hours after Bell filed for his patent, Elisha Gray filed for a patent as well. Therefore, in the 1860s and 70s, people were obviously ready for the phone to be released. And, when it was released, the first words used were, “Mr. Watson, come here, I want to see you.”

The telephone works by taking acoustic sound, converting it into electrical signals and then converting those signals back into acoustic sound to be heard. However, it takes precise parts to ensure that the sound that you are transmitting is received and converted into the correct words. If the phone is of a low quality, the sound becomes mumbled and this reduces the clarity of the sound.

When you pick up the phone and say “hello,” the voice causes a thin metal coating (these days we use plastic) over an electrode to move closer to the electrode. When this coating moves closer to the electrode, it creates a difference in voltage. This voltage is the result of a very fast conversion from acoustic sound—you speaking—into electric sound.

The important fact is that the acoustic sound is converted into electrical signals before it is transmitted. Transmitting sound through metal pipes is very ineffective and the sound dissipates before it reaches the person. However, converting to electrical signals first and then transmitting through a wire creates a very insulated scenario. This results in the signal being strong when it is received by the other person’s phone. And, because it is an electrical signal, it travels at the speed of light rather than the acoustic speed of sound.

Once the electric signal reaches the headset of the phone, the electrical signals are converted back into acoustic sounds. It’s this acoustic sound that is heard in the ear. It should be noted that digital phones work in a similar fashion. Cell phones, as well, function similarly. The basic principle is turning acoustic sound into a different type of wave.

The phone has revolutionized the world and is considered one of the most important pieces of technology for communication behind the printing press. It changes the way business was done and without the phone, things would be done much slower.