This is just a simple mod that aims to improve the engine sounds for the F-22 to more closely match the sounds of an F-22A. The default sound to me sounded weaker and has less bass than what you actually hear from a real F-22. I based the audio on the F-22 Demo Team I saw in person.
Go to the sound file for the F-22 which is located here for Steam users (if installed on a different drive just go to the MSFS folder and then follow the file location. If all else fails, try searching topmachstudios-ffa-raptor-premium in the file explorer.) C:\Users\"name"\AppData\Roaming\Microsoft Flight Simulator\Packages\Official\Steam\topmachstudios-f22a-raptor-premium\SimObjects\Airplanes\raptor\sound
Find the file named sound.cfg and make a backup copy of this file in case you wish to go back to the default sound.
Simply just copy, paste, and replace the original file with the new one and enjoy! You will notice that the F-22 will now have more rumble and overall sound more powerful.