Currently Being ModeratedMay 21, 2013 5:29 AM (in response to knsimko)
Did you record the people speaking as vocal tracks in a GarageBand project? Then the recorded audio files in the GarageBand package should still be showing the date you recorded the audio samples.
Select the GarageBand project in the Finder and ctrl-click the Myxxxxxx.band package. Then select "show package contents" from the pop-up menu.
You will see a Finder window showing the files and folders in the package. Open the "Media" folder inside. There you will find the voice recordings. When you select the recordings you will see the "Date created" in the file information, for example.