Читать книгу Electronics All-in-One For Dummies - Lowe Doug, Doug Lowe - Страница 16

One of the most common applications for electronics is making noise. Often in the form of music, though the distinction between noise and music is often debatable. Electronic devices that make noise are often referred to as audio devices. These devices convert sound waves to electrical current, and then store, amplify, and otherwise manipulate the current, and eventually convert the current back to sound waves you can hear.

Most audio devices have these three parts:

 A source, which is the input into the system. The source can be a microphone, which is a device that converts sound waves into an electrical signal. The subtle fluctuations in the sound waves are translated into subtle fluctuations in the electrical signal. Thus, the electrical signal that comes from the source contains audio information.The source may also be a recorded form of the sound, such as sound recorded on a CD or in an MP3.

 An amplifier, which converts the small electrical signal that comes from the source into a much larger electrical signal that, when sent to the speaker or headphones, can be heard.Some amplifiers are small, as they need to boost the signal only enough to be heard by a single listener wearing headphones. Other amplifiers are huge, as they need to boost the signal enough so that 80,000 people can hear, for example, a famous singer forget the words to “The Star Spangled Banner.”

 Speakers, which convert electrical current into sound you can hear. Speakers may be huge, or they may be small enough to fit in your ear.