I've just looked at the Neuomonics website to try to work out exactly what the 'Sanctuary' product which the US Army paid to have developped does:
http://neuromonics.com/treatment-options/sanctuary/
Information about the product itself is very sparse with most of the copy being fluff about
'finding relief from tinnitus' and how much
'expertise' Neuromonics can offer, and no price is given.
It seems that the player has three pieces of music loaded onto it in some form of lossless format and that each of these pieces of music has a
'customised high frequency signal' mixed into it which quote
'covers the tinnitus and provides an immediate sense of control and relief for the tinnitus sufferer', it is also possible that some kind of equalisation is applied to the music to match your audiogram, but this is inferred and not stated explicitly. It is made clear that this is not a treatment device, but is instead designed to give 'situational relief to mild to moderate tinnitus sufferers' at times when the tinnitus becomes bothersome.
The protocol seems to be that you go to a participating hearing clinic where your tinnitus frequencies are measured and these are then sent together with your audiogram to Neuromonics who load the modified audio files onto the device and send it to you with a guidebook telling you how to use it, and then you are on your own
The Product FAQ on the Neuromonics website contains the following comment:
Why can't I just use my MP3 Player?
With the Neuromonics Sanctuary, the music you listen to is spectrally modified and customized with an embedded neural stimulus based on your audiological and tinnitus profile. We have an understanding of the importance of auditory stimulation at high frequencies, and have built this into the Sanctuary. This type of stimulation is not possible with MP3 Players because the sound files stored in MP3s are clipped. Additionally, music on an MP3 Player is not customized for the individual's hearing profile. Due to the customization of the Sanctuary device, it is able to provide acoustic stimulation to a wide range of auditory pathways at comfortable and safe listening volumes.
Sure, low bitrate MP3's are clipped, but lossless formats such as WAV, FLAC, Apple lossless, APE, WV etc. aren't and you would be hard-pressed to find a modern mp3 player that doesn't support at least one lossless audio format. I feel this comment borders on misrepresentation and clearly a very similar effect
could be achieved by simply uploading the music files generated by Neuromonics onto a modern MP3 player or smartphone and listened to with a decent pair of headphones (Neuromonics offer Bose or Sony in ear headphones as an option)
Apart from the professional evaluation of your tinnitus frequency in the clinic, it doesn't appear to me as if the 'sanctuary' product is offering much more than 'AudioNotch' offer for $75 (though AudioNotch is in MP3 format and has no equalisation applied), or what you can do yourself for free by following the instructions in the thread about notched music therapy on this website
How much did the US Army pay for the development of this product and how much markup are Neuromonics themselves making on this device (as no prices are mentioned one has to assume the 'sancturary' products are rather expensive)? Now we see how profitable the hearing aid industry can be!