You can read some details about the 3DTI Toolkit spatial audio implementation.
The code is available from the GitHub account.
An example of the functionalities of the Test Application can be found in this video (use headphones when listening):
and here is a video demonstrating the hearing loss/hearing aid functionalities:
The Test Application (the one you see in the videos) is available for MacOS, Windows and Linux in the GitHub releases page, where you can also download the VST plugin, both for MacOS and Windows.