It seems the only way to create .frg files (Sound Forge projects) is with the program itself as no 3rd party software can create the files. Sound Forge supports a plethora of audio formats, so you can import .aa3 files to it and use them for making a new project.
Convert Sony ATRAC audio file to Sound Forge project file.
We found one software available in the database for this conversion.
Microsoft Windows software - convert aa3 to frg on Windows
A Digital audio editing software from Sony
Convert from aa3 file format
|Yes, Sound Forge supports aa3 file conversion as a source file type.||Yes||Yes||aa3 editor||Yes||No||No||No|
The table with program actions contains information about what each program is capable of doing with their files. This may be a good pointer for further searches for certain file conversions and help you find the converter you are looking for if our search result is insufficient for you. However, it is far from perfect and may sometimes show results which are not really usable because of the nature of the software handles the files. So a conversion that appears as possible, just because of matched actions, may in fact not be possible.