Starkey Wi i110 - Question for an expert

I’m trialing this (alongside Widex Clear 440). Model is the RIC with 312 battery, open fit.

I’ve got the Inspire printout of the current settings. I’m looking at the settings tables for each Memory slot. In each table, the “overall” input is 64db, the “soft” input is 50 db, and the “loud” is 80db. For some frequency bands, notably those below 1 kHz and those above 5.5 kHz, the values in the table are below the input value. ie. It appears that the output is actually attenuated relative to the input. This is true, even for bands where the CR (compression ratio) is unity. For each band, all figures are well below the maximum output.

Question: How can the band produce an output lower than the input when the CR is unity (not to mention that for some of the readings, the input amplitude is below the kneepoint)?

My audiologist couldn’t explain this. (She’s looking into it.) I’m guessing the answer is that input db is defined as an average for the whole frequency spectrum, whereas the outputs are for individual bands, but I’d appreciate confirmation (or refutation) from someone who intimately understands this.

Many thanks, -Ron

Understanding this involves realizing that the level at which a sound leaves your hearing aid (which is what you imagine the output would be) is NOT the same as the level at which that sound reaches your eardrum (which is the output level your printout is attempting to estimate). The difference between these two levels will be determined by the acoustic properties of your ear canal with a hearing aid stuck in it and will vary for different frequencies.

enjoy the bagel… don’t worry how they made it

enjoy the bagel… don’t worry how they made it

Excellent!

Some posters here seem to ‘think too much’ about hearing aids.

In reality there is NO silver bullet.

The ‘first fit’ followed by fine tuning based on the client’s preferences is really what happens with most fittings.

REM, in-situ audiometry etc all end up up with the almost trial-and-error final tuning step.

Thanks for the response. I think you refer to SPL. I’ve read about it but, true, my question didn’t consider it. So let me alter it.

I guess what I’m asking is, if the algorithms are smart enough to calculate the SPL at each frequency, why aren’t they smart enough to to deliver the input at a level that doesn’t effectively attenuate the input? Shouldn’t my perceived levels be flat across the spectrum?

Thanks, Ron

Thank you for responding to my question. Sounds like the entries in the printout are scaled to SPL. (The table does not state that explicitly.)

That leaves me wondering. Why would such sophisticated algorithms as now exist in these devices not adjust the amplitude so that there’s not even a perceived attenuation at any frequency? I’d have thought the goal is to present the hearing deficient user with a perceived flat response across the frequency spectrum. But if that’s not technically achievable (or desirable?), why not at least boost the whole curve so the lowest (SPL) point is at unity with the input?

Incidentally, this is more than just academic interest, since I get a sense of low frequency deficiency with this device.

Anyway, I appreciate the, er… feedback.:slight_smile:

-Ron

EDIT - Sorry for double post. Don’t know why. There was a server error yesterday, which required me to re-register. It also wiped my sig with audiogram. Will fix.

dB HL vs db SPL is a separate matter, unrelated to the “curious” behavior of the printout you’ve been looking at. If you Google HL vs SPL you should be able to find how the units are related and why both are commonly used if this is a subject of interest to you. In a nutshell, by using dB HL we’re able to graph your hearing test results in a way that is easier to understand and more meaningful to most patients. For most other situations we’ll use dB SPL.

And yes, your hearing aids are “smart enough” to estimate the attenuation, but again: The acoustic properties of your ear canals will differ from those of someone else and are unique to your ears. This will also be affected by whether or not you have a hunk of plastic or rubber partially filling your ear and how occlusive it is. Your hearing aids can only ESTIMATE the actual level at which sound reaches your eardrum. This depends on a lot of variables, which can’t effectively be described in one or two short paragraphs.

To simplify the fitting process, most of these (and other complications) are hidden behind the scenes so that you simply have an “input” and an “output.” We generally try not to go too far beyond this simplified description with our patients because in most cases I think we confuse them more than anything else.

That’s what most people would assume, but unfortunately isn’t the optimal approach. Most fitting formulas set hearing aids to provide roughly 1/2 to 1/3 of the loss at a given frequency in gain. If you’re curious as to why this is the case researching hearing aid fitting formulas would be a good place to start.

This often simply isn’t possible. In the case of an open-dome or highly-vented earmold a hearing aid can provide very limited (if any) low-frequency gain and any low-frequency sounds you hear are simply passing through naturally into your ear without the hearing aid playing a role. Generally, this will mean that “input”=“output” for low-frequency sounds, but since just having the hearing aid physically sitting in your ear can affect the acoustic properties of your ear, this may prevent “input”=“output” at certain frequencies even when the hearing aid is turned off.
This could potentially be “resolved” by using a more occlusive dome or earmold that plugs your ear, but would lead to other (often) rather undesirable problems (e.g. the “talking in a barrel”-effect).

I’m not sure if I’ve cleared things up or simply made things more confusing for you, but these can be rather complex topics. Often what seems like a simple, straight-forward question in the hearing aid world is much more complicated than you’d suspect!

I can’t say I understand it as well as I’d like, but no I’m not more confused, and I thank you for taking time to explain and to suggest entry points for reading on my own.

As a desktop music hobbiest, I’m familiar with multi-band compression, etc., so I do have a simple curiosity about the similarities vs. differences between (digital) audio recording vs. HA technologies. More important, I figure the more I know about the device(s) for which I’m being fitted, the more efficient will be the time spent with my audiologist. She, like you, appreciates this. She has some deficiencies, but (perhaps unlike others here) belittling me for asking questions is not one of them.

Many thanks! -Ron

Ron,

As a desktop music hobbiest, I’m familiar with multi-band compression, etc., so I do have a simple curiosity about the similarities vs. differences between (digital) audio recording vs. HA technologies. More important, I figure the more I know about the device(s) for which I’m being fitted, the more efficient will be the time spent with my audiologist.

In reality, you will stress her out because you will be challenging her actions - or at the very minimum asking for in-depth explanations. She may feel threatened and will certainly have to allow a lot more time for your fitting sessions … possibly with no great benefit to the fitting.

She, like you, appreciates this.

Are you sure about this? Maybe she needs the business and will go along with your questioning.

She has some deficiencies,

Hmm - so why work with her - or trust her - on such a technically challenging project as jointly tuning your hearing aids? Maybe it’s time to find a new audi.

but (perhaps unlike others here) belittling me for asking questions is not one of them.

The customer is always right!

Don’t get me wrong, I have MANY technically aware clients who come to me because I have a software background. I am VERY happy to spend a whole day discussing technicalities with them rather than spend a more usual half-day.

However don’t assume that all dispensers are like me. I know that many DREAD a technically oriented client.

To be frank:
“As a desktop music hobbiest, I’m familiar with multi-band compression” is NOT an audiology qualification and doesn’t make you ‘equal’ to your dispenser. It is also NOT a free ticket to an in-depth audiology course to be provided with your hearing aids. Most dispensers (but not me!) would dread hearing such a comment.