No option for external mic input

Hello,
I searched all through Preferences and Devices and don’t see any option for external mic- only built-in input and output. Any suggestions?? Thanks

It would help if we know what Mac you are using.

Audacity is a slave to the machine it is running on. You won’t see an option for an “external mic” because there isn’t one. To use an external mic on a Mac you’ll need an external adapter. Once you attach one of those, it won’t show up as “external mic”, but as some sort of description of the device, such as “USB Audio Input”.
– Bill

If you have an older MacBook Pro like this one…

http://www.kozco.com/tech/audacity/pix/MacLineIn.jpg

There is no direct, formal connection for an external analog microphone. There is a Secret Aural Teachings of a way to break into the microphone portion of the headset connection, but I’ve never done that and it may be a fable.

Depending on what kind of microphone you have there are a number of ways of connecting to your Mac. So that’s what kind of Mac and which microphone?

I have a 15" MacBook Pro with OS-X 10.9.5. The 13" has different connections and the newer ones are more different yet.

Koz

Thanks for your replies- I have a Mac OS X 10.6.8, and I have a professional USB mic, so I thought if I plugged it in directly to the USB slot it would register…?
So sounds like getting an adapter would be the best option?

if I plugged it in directly to the USB slot it would register

To the Mac yes, but you may need to restart Audacity. Audacity checks for new devices when it starts.

Koz