http://en.wikipedia.org/wiki/Teddy_Ruxpin
http://en.wikipedia.org/wiki/Audio-Animatronics
I think I did, and now I feel inherently awesome.
A normal (non-Teddy) cassette tape is designed for stereo playback with two distinct tracks on each side for the left and right speakers. In contrast, a Teddy Ruxpin cassette uses the two tracks differently: the left track contains the audio, while the right track encodes the toy's movements. A special hole in the top of the cassette tells the teddy bear that the right track contains movement data.
http://en.wikipedia.org/wiki/Audio-Animatronics
uses tones recorded on tape to vibrate a metal reed that closes a circuit to trigger a relay, which sends a pulse of electricity to a mechanism that causes a pneumatic valve to move a part of the figure's body.
The movements of the attraction's birds, flowers, and tiki idols are triggered by sound, hence the audio prefix. Figures' movements have a neutral "natural resting position" that the limb/part returns to when there is no electric pulse.
I think I did, and now I feel inherently awesome.