Speaker 1: Welcome to brain Stuff from how Stuff Works dot com
Speaker 1: where smart Happens, Hi Marshall Brain. It used to be
Speaker 1: that answering machines all used tapes, and some still do,
Speaker 1: but today most answering machines are digital. They use the
Speaker 1: same kind of technology that a CD or MP three
Speaker 1: player uses. The first step in the process is an
Speaker 1: analog to digital converter. This device samples the voice maybe
Speaker 1: eight thousand times per second, and gives a digital value
Speaker 1: to the intensity of each sample. A micro controller stores
Speaker 1: all the samples in low power RAM or flash memory.
Speaker 1: So let's say that a caller leaves a ten second
Speaker 1: message that might translate into eighty thousand bytes of digitized data.
Speaker 1: Those bites are stored at a specific address in RAM.
Speaker 1: To play the message back, the micro controller reads the
Speaker 1: eighty thousand bites from RAM and plays them through a
Speaker 1: digital to analog converter. RAM or flash memory is a
Speaker 1: high speed memory device, so the micro controller can erase
Speaker 1: one of the messages, it can easily move the other
Speaker 1: messages forward into the freed up space, or it can
Speaker 1: store a new message in the blank space. Do you
Speaker 1: have any ideas or suggestions for this podcast? If so,
Speaker 1: Please send me an email at podcast at how stuff
Speaker 1: works dot com. For more on this and thousands of
Speaker 1: other topics, go to how stuff works dot com.