Open your audio editor and configure it to create the format you wish to use. Audacity is a free, open-source software used for these examples. To create interleaved stereo, open a new project and add a stereo track by selecting "Tracks" from the menu bar, "Add New" from the drop-down window and "Stereo Track" from the submenu.
Record your audio material. Audacity, like most audio editors, automatically assigns the left and right data from your sound card or stereo audio interface. Using a multi-channel interface may require further track assignment. See your interface documentation for further details.
Save your recording as an interleaved file by selecting "File" from the menu bar, "Export" from the drop-down menu and choosing a WAV file format.
Create dual mono files by first clicking on the audio track name button on the left of the track. Select "Split Stereo Track" from the drop-down menu and your stereo track will be converted to dual mono tracks. Save each track with a unique name, using the export method described above.