The Impulse Response Utility project file is a Mac OS X package file, that contains all files associated with the project.
Impulse Response Utility automatically saves your project as soon as you record audio (see Automatic Saving of Projects). You can manually save your project at any time, however. You can also open a previously saved project, or revert the current project back to its last saved state.
Choose File > Save Project (or use Command-S) to save your IR Project with its current name, in its current location.
Choose File > Save As (or use Command-Shift-S).
If you’d like to continue working on a previously saved project, you first need to open it.
Choose File > Open Project (or press Command-O), then navigate to your project file.
Choose File > Open Recent to open a hierarchical menu of recently opened project files.
If you are unhappy with the edits or recordings made in your current project—and you have saved the project—you can use the File > Revert to Saved command. This returns the project to its last saved state.
Note: Once you use the Revert to Saved command, you will lose all unsaved changes.