Haven't tried any of it. Tomatis sounds reasonable for general hearing improvement. It's also quite good for Tinnitus sufferers. Various famous people including Sting and Yehudi Menuhin speak very highly of it. Some people use the training for learning new languages as it trains their ears to hear sounds that are in different languages which are unlike their own language. Opera singers also take the training as they can have issues with hearing and you cannot sing or speak what you cannot hear.
A copycat company formed by someone who was a patient of a Tomatis practitioner back in the 1970's, uses the technology but in a basic format without the complete understanding and implementation of the total system or equipment. They sell their copied technology from Australia in what I consider an overpriced format.
Basically what they do, you can do it in the privacy of your own home for free (in my case)
Get some good quality recording of classical music with lots of high notes such as violin etc - Mozart, Bach, Vivaldi for instance.
Take the files and do one of two things depending on what equipment you have. If you are a musician (Skinnydevil) you run it through a graphic EQ and dial out the frequencies 8000 and below. But you start by dialling out the lowest frequencies say on the first or second song then gradually dial out the frequencies so that after say 1/2 hour you have totally knocked out 8000 hz and below (bass notes)
Then you take more files and knock out the 8000 and below till you have a few hours at least. The more different files you have the better as you will go nuts if you have to listen to just a few pieces over and over again. Then with the last recording you do the reverse of the first half an hour. Put this on your iPod and listen to it at least a couple or three hours a day or as long as you can stand and are able. You can also listen to it as you are going to sleep. I am thinking you need a minimum of a few hundred hours of this to get results depending on the person.
You can also do the same filtering on a computer program like I have called "Sound Studio". You go to Sound Studio/Filter/Graphic EQ and dial it out. Keep the file large, ie do not compress so the integrity of the sound is there.
It will sound very high like a very cheap record player without a bass speaker. This is what you want. Also make it louder in the right ear than the left. Dr. Tomatis determined that persons with left ear dominant have issues (honestly I can't explain that one as I forget, but it is in his books.) He says that people who are left handed can be changed through the training of the right ear to be dominent.
In the Tomatis technique they try to get a recording of the mother's voice for some of the treatment, as that is the voice we heard in the womb. They also use a headset with a bone conduction speaker.
The rest of the info can be gotten online.