I was fitted with Oticon Epoq open fit hearing aids the other day. After the initial setup, the audiologist asked me how they sound and I said they sounded extremely tinny. He then selected another setting which greatly reduced the tin sounds. I asked him what he did and he said he set the aids to the manufacturers recommendations.
However, later when I was looking at the display I noticed a graph and asked the audiologist what the graph was indicating and he said he thought that the line indicated the gain that was being applied by the hearing aid and the shaded area was the maximum gain of the aid (2cc coupler gain).
After I left his office I discovered that the aids didn’t appear to be performing that well and started to think about the graphs that I saw during the fitting process. Since my audiogram indicates that I have a high frequency loss in both ears (about a 40 DB loss at 1500 Hz to about an 80 DB loss at 3000 Hz), I wondered why the graphs indicated that only about a 15 DB gain was being applied for those frequencies. This is strange since the specifications indicate that between 40-50 DB gain (using 2cc coupler tests) should be able to be applied for those frequencies.
Next week I have another appointment with the audiologist and I’ll ask him to increase the high frequency gain but I’m not sure that I’ll be able to stand the extreme tinny sound. Even at the current setting, I occasionally hear the tinny sound and when I do, clarity appears to suffer.
Why do the Epoq aids produce such a tinny sound? Is it caused by a poor quality receiver (speaker) or by some other issue with the aids?
Previously I was fitted with Widex Inteo CIC hearing aids that have similar maximum gain characteristics as the Epoq (but about 5 DB greater) and they were much clearer (no tinny sounds and voices were clearer) but I still had some problems hearing certain people so I tried different aids. However when I tested my own hearing using my computer, those hearing aids only produced gains of between 20-25 DB in those frequency ranges (1500-3000 Hz). I initially came to the conclusion that the limited gain was caused by the accustics of the ear but now I think that the hearing aids were set to only develop that much gain.
I now realize why my hearing has not improved as much as I had hoped. With either aid (Inteo or Epoq), a 15-25 DB gain will probably not allow me to even minimally hear voice harmonics between 2200-3000 Hz and will probably only allow me to minimally hear voice harmonics at 2000 Hz.
So with all the available maximum gain of the aids, why is the default gain set so low? Is feedback causing the aids to be set with so low of a gain? If I was fitted with the Widex Inteo BTE model with a similar maximum gain (5 DB more) as the CIC (but a fitting range of 10 DB more), would this help me get much more gain or will the increased gain only be slight since both the CIC and BTE aids are occluded aids?