You'll only need (at least I think so) a recorder application, as a hardware mic is already present (and is used for voice recognition by the system).
If you are working in OSX, I recommend AudiocorderX or Audio In if you want something simple, Sound Studio if it may be a bit 'more' (this has waveform editing and several effects).
These apps can be found on <a href="http://www.versiontracker.com"; target="_blank">versiontracker</a>. You can search on their name or on a keyword like 'recording'.
If you have any additional questions, feel free...
Comments
If you are working in OSX, I recommend AudiocorderX or Audio In if you want something simple, Sound Studio if it may be a bit 'more' (this has waveform editing and several effects).
These apps can be found on <a href="http://www.versiontracker.com"; target="_blank">versiontracker</a>. You can search on their name or on a keyword like 'recording'.
If you have any additional questions, feel free...