SoundRecover 2 is the Phonak frequency lowering technology. They do this generally by compressing the higher frequency sounds (called the “source” range) into a lower frequency range where you have better audibility (called the destination range). I think SoundRecover 2’s destination range can go as low as around 700-800 Hz).
Speech Rescue (not MoreSound Booster which is something else entirely) is the Oticon frequency lowering technology. They don’t do frequency compression, but they do this by “transposition” and “composition”. Transposition is taking a chunk of the sounds in the high frequency (source) range and transpose those sounds into the lower frequency (destination) range. Composition is because they cut up the source range into 3 sections, then transpose them into the same destination range but they stack these 3 sections on top of each other (hence composition). Unlike the Phonak’s SoundRecover destination range which can go as low as 700-800 Hz, the lowest Oticon Speech Rescue destination range is between 1.4 to 2 KHz.
I think how Phonak does frequency lowering via compression versus how Oticon does frequency lowering via transposition and composition is not as important as how low they can go on the destination range. Obviously Phonak has a leg up there because its destination range can go much lower than Oticon’s destination range. Specifically for your situation, your loss at 1 KHz is around 80 dB, but your loss between 1.4 to 2 KHz is between 90-95 dB, meaning that you can hear better at 1 Khz than at 2 KHz, so Phonak can lower the high frequency sounds to a more audible hearing region for you than Oticon can.
For your hearing loss, like you said, your HCP wants to maximize the usability of your existing hearing range, which is rather narrow, so I’m assuming that for sure he (or she?) will want to apply frequency lowering for you. I think your hearing loss can benefit tremendously with frequency lowering, it’s almost a must.
While you’re trialing the Oticon Real, make sure that Speech Rescue is enabled for you, and that the destination range is set to the lowest possible (the leftmost configuration 2.4). Turn the Strength value to max, and turn OFF the High Frequency bands because your loss is so profound in those bands that there’s no need to try to amplify sounds in the high bands anymore anyway. This should help with potential feedback whistling that you may not know about. Of course when you start to trial the Phonak Lumity, also make sure that SoundRecover is enabled for you, also preferably at the lowest possible destination region.
Although you may think the 85 dB receivers can handle your loss in the usable hearing region you have left, the 105 dB receivers would be better for you in many respects, and in either cases, with custom molds for sure. First off, the 105 dB receivers won’t be driven as hard as the 85 dB receivers would for your level of loss → maybe longer life, perhaps less saturation/max out/clipping which you may hear as the tinkling or buzzing that you describe. But your HCP should also ease up on the gain above 2 KHz like @Um_bongo suggested. One simple way to do it on the Oticon Real is just to turn OFF the High Frequency Bands amplification in the Speech Rescue menu, and the gain curve will be re-prescribed accordingly. But your HCP can also manually dial it down in the Fine Tuning section for you as well if that’s how they want to do it.
That leads to my next suggestion, have 2 program where Speech Rescue is ON for one and OFF for the other so you can do A/B program toggle comparison on the fly. That’s the best way to know how much Speech Rescue can be helpful for you, or not. And if this is the case, then your HCP would want to manually dial down the high frequency amplification in the Fine Tuning section to remove the “tinkling” which we’re guessing is due to the saturation of the 85 dB receivers.
One last thing to mention is that if the above suggestions doesn’t remove the “tinkling”, it’s possible that what you’re hearing is not tinkling, but “fluttering”. Oticon has a new feedback prevention technology called the Optimizer that inserts “breaks” (technically called Spectro Temporal Modulation) to stave off and disrupt the energy potential that can cause feedback. But the side effect of these breaks is that they may be audibly noticed by some people (depending on their hearings). So if the tinkling doesn’t go away, it may actually be the fluttering from the Optimizer. If that’s the case, then usually turning down the Feedback Management setting in the Automatics page in Genie 2 from Normal to Low would alleviate the fluttering.
I personally think that this tinkling is the saturation due to overdriving the receivers in the high frequency region, but since you said “feedback-like tinkling”, the feedback part that you happened to mention causes me to think that it may also be fluttering. When there’s energy buildup that has a potential for feedback, the Optimizer inserts the “flutter” (STM breaks) to break up this feedback potential. So at least now you have plan A (dial down the high frequency gain and use Speech Rescue) and plan B (dial down Feedback Management) to try to fix your tinkling issue.
