How do microphones work and why are there so many different types?

Like most other electronics, microphones have evoved greatly from the original device. The most modern versions convert waves of air pressure into electric signals, but different models do this in very different ways.

How Noise-canceling Headphones Work

Noise-canceling headphones maximize your listening experience by removing ambient noise, all without sacrificing the sound quality of your music. Learn how these cool devices differentiate between different types of sounds.

How Portable Media Centers Work

You can use it to watch TV shows and movies, listen to music and flip through digital photos -- all while sitting on an airplane. Learn all about the latest addition to the mobile-entertainment market.

How Tape Recorders Work

Magnetic recording is the backbone of the electronics revolution. Learn how this analog technology lets you store and erase data!

In a PA system how does feedback work to cause that howling sound?

We all know it, and it always makes us cringe -- it's that terrible howling of a PA system. Everyone calls it feedback -- what's "feedback"?