Sound file created by LEGO MINDSTORMS EV3, a program that enables you to create and program LEGO robots; contains audio recorded by the Sound Editor tool in the LEGO MINDSTORMS EV3 application.

To create the RSF file, select Tools → Sound Editor, record your audio, click Save, name the recording, and click Ok. To see your RSF file, go to your project, click the wrench icon, and select the "Sounds" tab. To export the RSF file, click the wrench icon in the top-left of the Project screen in the application, select your RSF file under the "Sounds" tab, click Export in the bottom of the window, name your file, choose the save location, and click Save. You cannot double-click the file to open it, you must import it. To import the RSF file, click the wrench icon in the top-left of the Project screen in the application, select the "Sounds" tab, click Import in the bottom of the window, navigate to the RSF file, select it, and click Open.