Speakers are transducers that convert electromagnetic waves into sound waves. The speakers receive audio input from a device such as a computer, cell phone, tablet, or an audio receiver. Speakers typically come in pairs, which allows them to produce stereo sound. This means the left and right speakers transmit audio on two completely separate channels. By using two speakers, music sounds much more natural since our ears are used to hearing sounds from the left and right at the same time. Surround systems can include five to eleven speakers and more (plus a subwoofer), which creates an even more realistic experience.