Higher gain leads to less speech clarity?

Hearing Aids
#1

I’m currently trialing Oticon Zircon 1’s with 105 dB custom earmolds.

During my first fitting a different HCP (since my HCP was on holiday) fitted my HAs. He accidentally fitted my HAs as 85 dB speakers:

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As you can see, the feedback manager shows a hefty amount of feedback. I’m not sure why this is, but this could be the explanation for my question (too much gain?).

During my second fitting my HCP noticed this was wrong and adjusted everything:

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As you can see, the feedback disappeared right away. The gains increased over the entire bandwidth as well as the MPO.

Yet, this increase in gain and MPO led to a more muffled sound. Background noises are also less present; in the old situation, a fan (for example) would make a lot more noise. Somehow, the level of clarity in the new situation decreased a lot. How is this possible? Since one would assume that more gain leads to better understanding and more background noises.

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#2

That’s due to the raised lows.

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#3

I can imagine that raising the lows increases the muffled effect.

However, it does not explain the following effects:

  • A fan or other devices that emit low frequencies are less noticeable with the second settings. While raising the lows would make one expect them to become more noticeable right?
  • Sounds/noise actually seem less loud. This should be impossible with more overall gain right?
#4

Check what frequencies that fan actually emmits, on Android you have apps like Spectroid to do that.
With the modified settings you have less contrast between highs and lows.
Other possibility is that something changed in the configuration of noise management.

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#5

Unfortunately there’s no app such as Spectroid on iOs. Is there any other app you would recommend?

#6

What about this one?
https://apps.apple.com/us/app/audio-spectrum-analyzer-db-rta/id1281873790

#7

Looking over the setting, my guess is the increased gain in the low level sounds is causing some algorithm/feature to go into suppression, or creating distortion in the processing… that’s could explain why the usual low level background sounds (which are often drones, hums) are less evident and intelligibility is lower.

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