Let me first explain what those terms mean. Not everyone on the internet knows about those technologies.

• HRTF (Head Related Transfer Function)[en.wikipedia.org]

HRTF is a technology that imitates how human anatomy affects sounds depending on their directions, providing a more accurate representation of 3D Sound with only 2 speakers or headphones. The advantage of this technique is that it can proccess nearly infinite directions unlike 7.1 or 5.1 surround systems.

Binaural Audio

Binaural audio is a form of 3D sound which requires only 2 speakers of a pair of headphones. Many people confused it with stereo in the past, but unlike binaural audio, stereo doesnt provide 3D sound. HRTF is often used for binaural audio due to how flexible and realistic it sounds.

X3D Audio HRTF[github.com]

96000hz HRTF Table (not included by default with X3D Audio HRTF, but needed for proper gunshot spatialisation in Estranged : Act II)
Dont forget to add the dot before com. I had to do this because steam tends to block mediafire links

http://www.mediafire .com/file/bkbf31a296zd3t3/MIT_KEMAR-96000.mhr

• Get to the X3D Audio HRTF github page (linked in previous section)
  
• Go to releases and download the latest x64 (or 32 bit if you are on 32 bit OS) release
  
• Paste all the files from the archive into this directory:
  Steam/steamapps/common/Estranged : Act II/Insulam/Binaries/Win64
  (or
  Win32
  if you are on 32 bit)
  
• Download the 96000hz HRTF table and paste it in
  Steam/Steamapps/Common/Estranged : Act II/Insulam/Binaries/Win64/hrtf
  (or
  Steam/Steamapps/Common/Estranged : Act II/Insulam/Binaries/Win32/hrtf
  if you are on 32 bit

If the directions do not "feel right", you should bake your own custom HRTF tables and replace the default ones with your own. You can find the tutorial for it here

• Kosumosu (X3D Audio HRTF)
  
• Martin.Kosecky5 (this tutorial, the 96000hz HRTF table, video preview)
  
• Olivier Warusfel (His HRTF samples were used as a base for the 96000hz HRTF table)