Apple PowerBook (5300 Series) - Manual (Page 74)

Connecting sound input and output devices
Your computer has a built-in microphone. For information on using the
microphone to record sounds, see the “Sound” topic of Macintosh Guide,
available in the Guide (h) menu.
Your Macintosh PowerBook also has a stereo sound input port (marked with
the √ icon) for connecting external sound input devices that provide line-
level output. You cannot use the internal microphone and an external sound
input device at the same time. For instructions on selecting a sound device in
the Sound control panel, see the “Sound” topic of Macintosh Guide, available
in the Guide (h) menu.
The Macintosh PowerBook also has a stereo sound output port (marked with
the - icon) to which you can connect externally-powered speakers, an
amplifier, headphones, or other audio output devices. The sound output port
accepts a standard stereo miniplug, like that used to attach headphones to a
portable tape player.
Microphone
63 Connecting Additional Equipment