Audio Environment General Aviation Edition makes flying the default FSX aircraft a whole new experience. The product is in final stages of development and should be released in the early part of next year.
These sounds can also be used in third party aircraft using a simple utility provided, which backs up your existing sounds and replaces them with fantastic new hi-fidelity sound sets. Restore the original sounds at the click of a button should you need to update the third party product.

The package features replacement sound sets for the default FSX aircraft below:

King Air 350
Cessna 172
Cessna Caravan
Extra 300
Piper J3 Cub
Robinson R22 Heli
Bell 206 Heli
Baron 58

Also included are general Rain and Thunder environment sounds and airport ground vehicles. Most FSX vehicles use the same sound set, so TSS have replaced them with vehicle specific sound files. A video demonstrating the additional sounds is in the pipeline, so watch this space.

In the meantime, enjoy the video below which first lets you listen to the default FSX sound, then shows the same aircraft with the new sounds.