Podcast recording on Mac OS X: avoid recording system sounds

You can avoid recording system sounds by routing them to a specific audio output that is not picked-up by your recording application.

Do this by selecting the desired output in the 'Sound effects' tab of the Sound system preferences. Set 'Play alerts and sound effects through:' to somehting other than 'Selected sound output device' or the channel that you are recording (for example: Soundflower.)

Im most cases 'Built-in Audio' will do fine. (See example below.)

Unchecking 'Play feedback when volume keys are pressed' will disable the sound you hear when you adjust your volume. (You can always hold down the shift key when you're pressing a volume key to temporarily change this behaviour.)

Sound system preferences

You can also choose to hear sounds when you perform certain actions in the Finder, by selecting the 'Play user interface sound effects' checkbox. If this checkbox is selected, for example, you hear a sound effect when you drag an item to the Trash.