Voice Over Guy

• Go to Finder
• press CMD+SHIFT+A
• go to QuickTime Player
• select it and open it
• once open go to the Menu Bar
• click FILE
• then click NEW AUDIO RECORDING

the input should already be set to the internal microphone​

• now click the round button with the red dot in it to record your voice
• click that button again (now it has a black square in it) to stop the recording once you finished what you wanted to record
• then go to FILE and click SAVE AS and save it where you want

Sadly QT Player is not smart enough to save it as a .wav or .aif or .mp3 or any other audio file format, but saves it as QuickTime movie (.mov), thus you can use iTunes to convert it to a proper format.

To do that

• open the .mov in iTunes (add it to the library)
• go to iTunes Preferences (CMD+,)
• then go to the GENERAL section in there
• then click IMPORT SETTINGS at the bottom
• under IMPORT USING select the appropriate format

(WAV and AIFF encoder are lossless and take about 8 MB for one minute of audio,
AAC and MP3 encoder are compressed formats, thus you can have, with the right settings, a file, that takes 1 MB per minute of audio​

• close the Preferences window via CMD+W
• select the mov file in your library
• right click on it
• click "Create ... version"
• right click on the new file
• select "Show in Finder"

Boom, there is your file.


Does that suffice?

Or, using just the built-in hardware, you could download this one-click recording application.