The presentation, just the slides are not very informative. I am going to try to find out more.
Comments on the slides:
There are very few people on this study, only 23 people.
On slide 23, there is only a 10 dB improvement at 8000 Hz (really, negligible improvement) for only 4 out of 15 people. That's like nothing, not worth pursuing any treatment just for that...
... that's just not true. I have had hearing problems for many years, and my hearing has gotten worse very slowly, progressively, and has gone faster in the last 3 years. Well, at the outset, with minor hearing loss at and above 6000 Hz (-25 dB), one can hear almost perfectly. Those frequencies are not important for speech recognition, and this is something accepted by most ENTs.
The important frequencies are in the low range, and in my case this is the big change I noticed, when 500 - 2000 Hz fall from 0 dB to -15 dB or -20 dB there is a difference in speech recognition in noise. And that's specific for that frequency range, for the low frequencies.