Using the built-in microphone
Your Macintosh comes with a built-in microphone to record live sounds. The microphone is highly sensitive. Once you’ve turned it on (which you do with a sound-recording program), it can pick up sounds within a range of several feet. See your Macintosh User’s Guide for information on recording sound.
Built-in 
microphone
sWarning: Do not stick any small objects into the built-in microphone. Doing so may damage your equipment. s
Installing an expansion card
The Macintosh comes with a slot inside called a processor-direct slot in which you can install a processor-direct expansion card for special purposes. Some expansion cards are designed so that you can install them yourself. Others can be installed only by an Apple- certified technician. To install a card, use the documentation supplied with the card you plan to install, or follow the instructions in this section.
sWarning: To avoid damaging your computer and expansion card, do not attempt to install any expansion card without first checking the documentation for that card. If the documentation specifies that an Apple-certified technician must install the card (usually because the installation requires special training or tools), consult the service and support information that came with your computer for instructions on how to contact an Apple-authorized service provider or Apple for service. If you attempt to install the card yourself, any damage you cause to your computer will not be covered by the limited warranty on your computer. If the card is not an Apple-labeled product, then check with an Apple- authorized dealer or service provider to see if you can install it yourself. s
