Phonak APD vs. DSL fitting formulas for "ski-slope" audiograms

You can choose to use DSL v5a (adult) in Target.

@brec

Thank you, I’ve just done this, and the difference is astounding. Everything is now very loud, but also much clearer I may have to reduce some mpo’s. I can see why this wouldn’t suit everyone

It didn’t work well with vented domes, as the dotted feedback line cut straight through the other lines, so I swapped back to full domes, and the feedback line is much higher.

Time will tell when I go to the pub!

Thank you
Peter

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Yes, more occlusive – less vented – domes (or molds) will raise the feedback threshold.

A dotted/dashes feedback threshold line indicates that Feedback and real ear test has not been run. It’s a good idea to run it. After running it you also have the option of “overtuning” (raising) the threshold in order to avoid its reducing the gains (“cutting through the other lines”) at higher frequencies.

@brec
I shall try that with dslv5. I found it reduced gains too much on previous.

Ideally, I’d prefer domes on these spare Marvels, for comfort

Better to drop the overall gain, the MPO will follow accordingly.

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Wow, just been outside, and down the pub. Switched to P90s before getting in the pub, they were booming, with a perceived upwards masking. Will try again tomorrow

The guiding ideal of DSL is audibility and the guiding ideal of APD is selling hearing aids. The latter goal should still end up somewhere reasonable since you can’t sell hearing aids over the long term if people cannot hear with them, but it does tend to lean a bit harder into “comfort and acceptance” rather than “rehabilitation”.

But the brain can’t hear what it can’t hear. And the brain adapts. Different people have different tolerances for rehabilitation. If you’re okay living with something that might start out sounding a bit harsh and giving yourself time to adapt, you may end up with higher function.

However, information that we do not have at this point are the time course and limits of that adaptation. So it can be admittedly frustrating not knowing how long you need to put up with something that isn’t perfectly comfortable in order to maximize gains.

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This probably is not the answer you are looking for but it is my experience.

I spent a lot of time tuning APD for the best speech understanding.

Then tried DSL. My speech understanding went down. I then fine tuned DSL over a months time for best speech. When best speech understanding was reached the gains turned out to be very similar to the APD gains from before.

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I’m late to the discussion, but I’ll throw in my 2 cents. I think OP MIGHT benefit from DSL because their high frequency loss isn’t too bad. They might actually benefit from more gain there. For profound high frequency losses (like my audiogram) seems like DSL throws gain to areas that can’t benefit. Remember that Phonak throws in frequency lowering (Sound Recover 2) as an alternative way to make high frequencies audible.

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Does “throwing” this gain have a cost that manifests elsewhere in the frequency range, or is the cost only potential loudness discomfort and/or feedback issues?

Can you describe or characterize what (kinds of things) you did in each case to achieve best speech understanding?

I think mainly the later. IF (I don’t think yours is, mine is) your high frequency loss is because of a dead cochlear area, more gain will add distortion.

I have this concern too.

…i.e., APD avoids harshness or discomfort that might alienate the user – regardless, I suppose, of the experience level indicated for the client. In this regard I note that Philips HearingSuite software for the (Costco) HearLink HAs offers two proprietary rationales: Fit4Speech (default) and Fit4Comfort. Help text says that Fit4Comfort is a non-linear rationale based on Fit4Speech and is most suitable for first-time users.

That’s a tuff question.

A big one for me was tuning each ear independently.

Learning from a pro that most self fitters under fit hearing aids also helped me a bunch. This led me to raise gains until uncomfortable then deal with it for a couple weeks. This was a very carefully done based on environments and frequency.

The last thing for me was frequency lowering. This was a game changer for me. My upper frequencies are gone so frequency lowering brought sounds in I have not heard in years.

Eventually my hearing got much worse in mid and lower frequencies and aids did not help enough for communication. I went the CI route which has been life changing.

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how different is the CL setting? compared to hearing aids? I haven’t seen it, so I’m interested in your experience, what you saw when they did it to you

Fascinating. I have similar loss.
DaveL

I have no idea. CI programming and hearing aid programming are very different.
My ears were not hitting on all cylinders with hearing aids but with the CI’s they are if you understood my meaning.

My point about APD and DSL had a lot to do with a person’s hearing loss. For those with less loss these fitting algorithms will probably make a bigger difference than for those with severe/profound hearing losses.

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I tried the dsl formula for a week on Unitron hearing aids. Although at first it seems that dsl is louder and I can hear sounds better, but I noticed that I don’t understand speech more often. So I switched back to the Nal nl2. Nalnl2 turned out to be quieter, but speech is better understood, and I noticed that over time the brain learns to listen to those quieter sounds that Dsl amplifies to be louder. They are Unitron hearing aids that do not have the phonak formula… I use another pair of phonak audeo paradise hearing aids, and I use the phonak formula and my impression was that the phonak has better accentuated deeper sounds. But over time, I slightly adjusted both hearing aids, so now the sounds are so similar to me that I hardly notice the difference due to the formula. I wear the unitron for more than half a day and then I wear the Phonak.

question, when buying a new processor, do I need to set it up again from scratch or can I use the old settings from the old processor?

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