Self-fitting and trainable hearing aids

Smithtr

Smithtr

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Siemens is funding, under the radar at the HEARing Cooperative Research Centre (CRC) in Australia, R&D to implement self-fitting and trainable hearing aids. Although their market is the Third World, in fact much of the technology can also be used here for "the provision of amplification devices outside of the traditional provider-client relationship" -- Talk about a disruptive technology way ahead of what UnitedHealthcare is doing now!

Here is a list of the publications, from earliest in 2009 until today:

• Client-Based Adjustments of Hearing Aid Gain: The Effect of Different Control Configurations
• The self-fitting hearing aid
• The Trainable Hearing Aid
• Many factors are involved in optimizing environmentally adaptive hearing aids
• The self-fitting hearing aid: a concept and potential advantages and disadvantages
• The audiometric threshold: measured in-situ, automated, and by the hearing aid [More on this in the first comment, especially as it relates to the Sensogram as implemented by Widex, obviating the need for probe mic (REM) testing]
• User preferences for amplification for adults with severe and profound hearing loss
• Perception and management of a self-fitting hearing aid among older adults
• Is inter-subject variation in measured directional benefit best explained by variation in acoustic, psychoacoustic, or cognitive parameters?
• How well can adults manage a self-fitting hearing aid?

Shared with Todd Houston, Greg Fox, Jason Galster, Anders Jensen, Sergei Kochkin, Nance Kruh-Meyer, Brian Kelly, Cathy Henderson Jones, and Jane Corless


Self-fitting and trainable hearing aids | HEARing CRC
 
Ha! I would love to train my own hearing aid! It would be like a little pet. :P
 
We already have DIY hearing aids. No need to wait

But we have done it already (blameysaunders).
For the past 10 years we have been working on technology that has allowed us to sell a self fitting hearing aid (DIY). We launched a year ago and have a a hearing aid system that was on the New Inventors and all news channels in Australia last April. The hearing aids don't use compression so we've been able to set up something that is very easy to adjust yourself. So, Australia already has a self fit hearing aid. And the good news is that we are doing this at a fraction of the price of top range, big company hearing aids, as our goal has always been to be consumer advocates and to help alleviate the problem of hearing loss.
 
ElaineSaunders said:
But we have done it already (blameysaunders).
For the past 10 years we have been working on technology that has allowed us to sell a self fitting hearing aid (DIY). We launched a year ago and have a a hearing aid system that was on the New Inventors and all news channels in Australia last April. The hearing aids don't use compression so we've been able to set up something that is very easy to adjust yourself. So, Australia already has a self fit hearing aid. And the good news is that we are doing this at a fraction of the price of top range, big company hearing aids, as our goal has always been to be consumer advocates and to help alleviate the problem of hearing loss.
Click to expand...

You have open fit hearing aids for people with mild to moderate loss, and I have put the image from your site for people to see the range.

The pricing from about $1000 to $1300 is about average or high for these types of aids, of which you are not the first manufacturer.

Hearing Aids | Blamey & Saunders Hearing Aids Online with IHearYou

20uwyn6.jpg


The OP about what Siemens is developing is really quite interesting, but your :spam: is a bit annoying.
 
Originally Posted by ElaineSaunders
But we have done it already (blameysaunders).
For the past 10 years we have been working on technology that has allowed us to sell a self fitting hearing aid (DIY). We launched a year ago and have a a hearing aid system that was on the New Inventors and all news channels in Australia last April. The hearing aids don't use compression so we've been able to set up something that is very easy to adjust yourself. So, Australia already has a self fit hearing aid. And the good news is that we are doing this at a fraction of the price of top range, big company hearing aids, as our goal has always been to be consumer advocates and to help alleviate the problem of hearing loss.
Click to expand...
This company in Brazil sells self fitting aids, at a fraction of your price, and they are rechargable, and fit a wider range of loss.

Solar Ear
 
@Smithtr: Thank you for copying and pasting my original post on Facebook. However, next time, please be courteous enough to give me the proper attribution.

Here is my original post from 11:48am EDT (Facebook sign-in required):
 
Cochlear America's did a research study on client self mapping to see if the clients results were better than if the Audiologist did it..
 
Here is the abstract from The audiometric threshold: measured in-situ, automated, and by the hearing aid:

The need for reliable access to hearing health care services is growing globally, particularly in developing countries and in remotely located, underserved regions in many parts of the developed world. Individuals with hearing loss in these areas are at a significant disadvantage due to the scarcity of local hearing health care professionals and the high cost of hearing aids. Current approaches to making hearing rehabilitation services more readily available to underserved populations include teleaudiology and the provision of amplification devices outside of the traditional provider-client relationship. Both strategies require access to such resources as dedicated equipment and/or specially trained staff. Another possible strategy is a self-fitting hearing aid, a personal amplification device that is equipped with an onboard tone generator to enable user-controlled, automated, in situ audiometry; an onboard prescription to determine the initial hearing aid settings; and a trainable algorithm to enable user-controlled fine-tuning. The device is thus assembled, fitted, and managed by the user without the need for audiological or computer support. This article details the self-fitting concept and its potential application in both developing and developed countries. Potential advantages and disadvantages of such a device are discussed, and considerations for further investigations into the concept are presented. Overall, the concept is considered technologically viable with the main challenges anticipated to be development of clear, simple user instructions and a delivery model that ensures reliable supplies of instant-fit ear tips and batteries.
 
One of the reasons why I *really* like in-situ audiometry as implemented by Widex, and by Cochlear in their BAHA device, is that these devices use the data directly to configure the gain in each channel, with no messy 2cc or REIG conversions between what is measured on a pure tone audiogram & how the hearing aid should be set, i.e. the diagnosis has already been made & the determination to use hearing aids has already taken place: The sensogram creates a new set of relative datapoints independent of absolute values that were recorded on the audiogram.

The following was taken from my correspondence with Prof Michael Valente at WUSTL in the use of the sensogram by Cochlear for their BAHA device when it is used for transcranial CROS; but it applies equally to how Widex implements it as well:

-----

The only time the difference between the relative and absolute sensogram values come into play is when you use the values for anything **besides** configuring the gain, MPO and compression knee setpoints, i.e. if the output from the DAC where a tone is just detected corresponds to 0x002D (hex), then that is what the DSP will use for the 1kHz channel as the multiplier to correspond to 0x0001 (0dB HL) acoustic input (or, of course, what is desired to be the minimum HL (or SPL) that will be mapped to 0x02D output).

Delving a bit deeper in a second e-mail, I wrote:

Basically, when you look at a hearing aid datasheet, you're looking at 2cc & graphs and figures that have to go through conversion factors & such to match up to the patient's ears, with additional conversion factors thrown in from real ear measurements, or for peds using DSL-5 age-dependant corrections; plus you have 6cc coupler corrections for the headphones, yada yada yada…

Now, let's take a clean sheet sheet of paper, and plug a hearing aid into the ear of a HOH patient. We don't know what his exact threshold is, and we don't care. To keep the numbers simple, let's say we're using an output amplifier with a maximum output of 1.0 volt RMS (we'll leave aside the hexadecimal portion of the calculations). The output in decibels (re 20 µbar) will be determined by the receiver sensitivity, but in fact it is a non-issue as far as the sensogram is concerned.

We then test the patient at 1kHz for two things -- Threshold and UCL -- and find that it takes 1 millivolt to reach his threshold, and 500 millivolts to reach his UCL. We now basically have everything we need to determine the transfer function for the channel centered at 1kHz. We then repeat these measurements for each channel, etc…

The beauty of this is that since we're measuring through the entire back end of the electroacoustic system -- from the receiver through the plumbing, plus any anatomy all the way to the inner & outer hair cells, treating it all as a simple "black box" -- we don't need to know anything else. This also applies if an inertial transducer for a BC/BAHA instrument is used, too.

Going back to our example at 1kHz of threshold at 1mV & UCL at 500mV, we now can construct an amplifier I/O transfer function at 1kHz. For our example (and to keep it simple), let us assume a 16 bit ideal ADC (96dB dynamic range), with the mic that is calibrated to the ADC to register over a 0dB to 96dB SPL input range, i.e. 0dB is 0x0000 (hexadecimal), 6dB is 0x0001, 12dB is 0x0010, and so on to 96dB being 0xffff.¹ We now plot two points on the I/O graph: (1mV, 0dB) and (500mV, 96dB), and then draw a line between those two points, and let the DSP perform the logarithmic calculations to create WDRC. In our example, the slope of the line will be:

20 log (V(2)/V(1)) dB
_________________ =
96dB

20 log (500mV/1mV) dB
__________________ =
96dB

54dB
____ = 54dB/96dB = 0.5625 dB per dB slope.
96dB

The beauty of the sensogram is that you're not piling up conversion factor on top of conversion factor, with all sorts of creeping tolerances: It's all direct, and the exact I/O parameters are passed through to the DSP. To give you an idea how powerful the sensogram actually is, America Hears (formerly Authorized Hearing Service from 1979 to 1999) uses this for user-programmed hearing aids, bypassing the need for probe mic measurements to get a precise fit.

Let me stress that my example above is a simple exercise and also it assumes a constant (logarithmic) transfer function: Any additional compression (say, a compression kneepoint at 60dB input) would result in that portion of the I/O graph having a shallower slope; and conversely any expansion (say, an expansion kneepoint of 18dB) having a steeper slope.

The only issue I can see with using the sensogram method with a BAHA is one of determining the ordinate of the right pair of coordinates if the maximum output does not reach the UCL, i.e. in our example above with a threshold at 1kHz of 1mV, the UCL would not be 500mV or even 1.0V: Is it 2 volts? Or 10 volts? This will throw off the dB/dB slope of the I/O transfer function calculation, as if it is assumed that 1.0V is the UCL, then the compression ratio will be too high, i.e. the slope too shallow.
 
Here's another article by Harvey Dillon & others on the subject of in-situ measurements; but as you can see from the abstract, he is conflating the relative vs absolute values measured in in-situ audiometry.

Abstract from "Threshold Measurements by Self-Fitting Hearing Aids: Feasibility and Challenges"

A self-fitting, self-contained hearing aid is a device that can be managed entirely by the user, without assistance from a hearing health care professional or the need for special equipment. A key component of such a device is an automated audiometer that will enable the user to self-administer measurements of in situ thresholds, which the hearing aid will use to prescribe a baseline setting for the wearer. The success of the device therefore depends on the validity and reliability of in situ threshold measurements and automatically measured thresholds. To produce a complete and self-contained device, the self-fitting hearing aid will also enable identification of audiograms that are contraindicative of hearing aid usage. The feasibility and challenges of achieving these characteristics are explored and discussed. While the overall concept seems feasible, several challenges were identified that need thorough investigation and/or development. These include the use of instructions to self-manage hearing aid insertion and in situ threshold measurements, selection of an appropriate transducer and instant-fit tip that will allow measurements of a wide range of threshold levels, control of ambient noise during threshold measurements, and self-manageable procedures that enable identification of such audiogram characteristics as asymmetry and conductive hearing loss.
 
Dan Schwartz said:
Here's another article by Harvey Dillon & others on the subject of in-situ measurements; but as you can see from the abstract, he is conflating the relative vs absolute values measured in in-situ audiometry.

Abstract from "Threshold Measurements by Self-Fitting Hearing Aids: Feasibility and Challenges"

A self-fitting, self-contained hearing aid is a device that can be managed entirely by the user, without assistance from a hearing health care professional or the need for special equipment. A key component of such a device is an automated audiometer that will enable the user to self-administer measurements of in situ thresholds, which the hearing aid will use to prescribe a baseline setting for the wearer. The success of the device therefore depends on the validity and reliability of in situ threshold measurements and automatically measured thresholds. To produce a complete and self-contained device, the self-fitting hearing aid will also enable identification of audiograms that are contraindicative of hearing aid usage. The feasibility and challenges of achieving these characteristics are explored and discussed. While the overall concept seems feasible, several challenges were identified that need thorough investigation and/or development. These include the use of instructions to self-manage hearing aid insertion and in situ threshold measurements, selection of an appropriate transducer and instant-fit tip that will allow measurements of a wide range of threshold levels, control of ambient noise during threshold measurements, and self-manageable procedures that enable identification of such audiogram characteristics as asymmetry and conductive hearing loss.
Click to expand...

Does that mean I could "tune" in the sound of distant thunder and "tune" out the sound of a siren at the same time?
 
You can't defy the laws of physics

ceelynncee said:
Does that mean I could "tune" in the sound of distant thunder and "tune" out the sound of a siren at the same time?
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You can't defy the laws of physics; however if there are particular sounds that are annoying, and they can be identified, then Yes, the DSP's can be tweaked… But this is provided only in the very top-of-the-line hearing aids.
 
Dan Schwartz said:
You can't defy the laws of physics; however if there are particular sounds that are annoying, and they can be identified, then Yes, the DSP's can be tweaked… But this is provided only in the very top-of-the-line hearing aids.
Click to expand...

You don't know do you? You don't know because you are hearing impaired. We don't know that. I'm unaided. Thunder and sirens are far out of my range. How many people, American citizens, are like me?
 
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