Linear Octave Frequency Transposition - LOFT

@gciriani said:

Thanks for your testimonial; I think it validates the research papers.

And for what it is worth, I have worn HA’s for over 8 years now and I found that my tinnitus volume has been lowered since I have worn them. None of my aids have had the tinnitus feature.

@MVPinFLA said:

I have worn HA’s for over 8 years now …

Mike,
How long have you had your Rexton Trax 42? I put my money down for that model yesterday; it is my first HA.

I got them 3 weeks ago. I am working on a write of my experience with them that I will hopefully post later today.

My biggest concern with frequency lowering is what I think of as addiction. So you buy a frequency lowering device and wear it and like it for years. Then some other technology comes out that is better but now it sounds crappy to you because now your brain is wired to what frequency lowering sounds like. Nevermind that what you are now accustomed to (frequency lowering) is completely unnatural and artificial and virtually impossible to duplicate unless you stick with that same brand and same implementation for the rest of your life.

Its like what all those people wearing analog hearing aids go through when they get their first pair of digital hearing aids. Some transition easily, but some have a really hard time transitioning

Just from a philosophical standpoint, it seems more reasonable to me to keep the signal as close to what it was naturally as possible. If a sound was at 8k, keep it at 8k. If a sound was at 1k, keep it at 1k… If you have NO processing ability at 6k or 8k, then yeah, lower that frequency! But if you don’t have to, then don’t.

This fact of people being “addicted” to what they are used to is why people have a measurable hearing loss, get fit with hearing devices, and then say things like, “It sounds too tinny” or “Wow, thats loud” or “That sounds echoey.”

People with a hearing loss like yours often get fit and then come back complaining about all the new sounds they are hearing. From the perspective of a dispenser, if you were going to hear everything exactly the way you are used to, then what was the point?

With my test procedure, I can measure almost every aspect of a person’s hearing, and I can predict almost every aspect of their end result. The ONE thing I cannot predict is their brain’s plasticity. How quickly will that particular brain adapt and accept the new sounds that it is unaccustomed to processing. MRI studies have SHOWN that how your brain processes sound CHANGES physically depending on the quality of the sound input. Your brain actually CHANGES which neurons activate depending on exposure to sound over time. But there is currently no test that is research proven to accurately predict how quickly this process will happen.

The point people are making is not bias. It is that LOFT, or any other new technology with research behind it, is not effective or beneficial to 100% of people all of the time.

And those two research papers are not where the research ended. Every manufacturer takes research like that and then builds upon it and implements a variation of it. Nobody does EXACTLY the same thing that was done in one study.

Look at frequency lowering as an example. Some implementations compress the frequencies into a narrower dynamic range. Some just transpose a duplicate of one frequency range down into a lower, but just as wide, frequency range. Some copy the higher frequencies down but leave the existing inputs intact as well just in case… They ALL have research supporting them.

As a real world clinician, I can tell you from personal experience that people switching from frequency lowering technologies to traditional amplification often have a harder time adjusting. Not ALWAYS, but often. And vice versa.

Additionally, don’t forget, MOST people do not lose their hearing suddenly. They lose it gradually over many years. So let me ask you this, what day (specifically) did you lose your first decibel? I’m sure you don’t know. So your hearing for the last 30 years has not been consistent for that entire 30 years. But I bet you never noticed the day by day gradual reduction that happened.

Why do you think so many people deny hearing loss for years until all of a sudden they get tested and they are missing 40 dB? How did they not notice it sooner?

@JustinHIS said:

… what day (specifically) did you lose your first decibel? I’m sure you don’t know …

You are right that I don’t know the exact time when I started losing it, but I have a pretty good idea in what year it started. I have about 10 audiograms during all these years; obviously I cannot notice the day to day change, but I can tell that every couple of years things get worse.

The problem is that when my wife started saying I needed a hearing aid (about 20 years ago) the audiologists (and I tried more than one in three different countries), they all were saying that my speech comprehension was good enough, and they didn’t see yet the need for a hearing aid. Even the Costco audiologist who is selling me the Rexton HA, said that I was a marginal case that could cope well enough, and it was up to me if I wanted it.

What is your test procedure? I’m interested.

If you truly want to know what your potential for benefit is, you must determine your potential binaural word recognition, AND you must determine your unaided binaural word recognition. The difference is your potential for benefit.

The best way to determine your potential word recognition is to begin with your audiogram.

For YOU, your binaural word recognition should be tested with ear inserts, using the NU-6 word list. (To keep my explanation simple, I will say to be tested on all 50 words) Both ears should be set to 75 dB. Your % correct out of 50 is your potential word recognition. There is, of course, a margin of error, but with 50 words, that margin is about +/- 3%.

Then, you should be tested in a calibrated sound field (no ear inserts, just a speaker positioned at ear level about 36" in front of you.) The speaker should be set to 50 dB (Some people prefer 45 dB to better simulate softer speech). You can use the NU-6 word list again (They make a few different lists so you don’t have to use the same one again), and repeat 50 words. Personally, I prefer to use the California Consonant Test word lists for this. This word list is weighted toward words with more high frequencies, making it more challenging for someone with a high frequency hearing loss. Some people feel this biases the test, but personally, I want to make sure my patients are able to understand the most challenging words, not just the average. If you have the time, you can certainly do both lists. More information never hurts. Regardless, this score is your current unaided word recognition.

So hypothetically, if your potential is 85% and your unaided score is 45%, you have a potential benefit of +40%. Then, after your devices are programmed, you can do the same unaided test again, but with your devices on. You should be able to get an accurate measurement of the improvement. So lets say hypothetically, your aided score is 65% at the manufacturer’s recommended settings. You have achieved a 20% improvement, which is enough that you will buy the hearing devices, but you have inadvertently fallen 20% short of how good it COULD be. So you have only gotten half your money’s worth.

You could even do the same thing both WITH your frequency lowering turned on AND with it turned off. Thats a really interesting test. I have had people with such horrible high frequency hearing that their potential score was very low, but then with frequency lowering activated, their aided score is actually much higher. But the reverse has also been true at times. People with high potential, and low aided scores with frequency lowering activated, but with very high aided scores without frequency lowering.

@gciriani said:

I’m not sure if you are referring to me, since there is no name nor quote.

Yes.

You have a moderate getting to severe HF loss.

@JustinHIS said:

If you truly want to know what your potential for benefit is, you must determine your potential binaural word recognition, AND you must determine your unaided binaural word recognition. The difference is your potential for benefit.

The best way to determine your potential word recognition is to begin with your audiogram.

For YOU, your binaural word recognition should be tested with ear inserts, using the NU-6 word list. (To keep my explanation simple, I will say to be tested on all 50 words) Both ears should be set to 75 dB. Your % correct out of 50 is your potential word recognition. There is, of course, a margin of error, but with 50 words, that margin is about +/- 3%.

Then, you should be tested in a calibrated sound field (no ear inserts, just a speaker positioned at ear level about 36" in front of you.) The speaker should be set to 50 dB (Some people prefer 45 dB to better simulate softer speech). You can use the NU-6 word list again (They make a few different lists so you don’t have to use the same one again), and repeat 50 words. Personally, I prefer to use the California Consonant Test word lists for this.

So hypothetically, if your potential is 85% and your unaided score is 45%, you have a potential benefit of +40%.

Actually that would be an almost 90% increase in your word recognition - almost double and only if you use the same test. When you are already talking about % scores it is better to talk about point increases so it doesn’t become confusing. But I’m sure we get what you are saying. I see why you want to use the more difficult test for the aided version but you could end up with the same score even if word recognition actually improved.

Hi,

Does anyone know if any Oticon products offer linear frequency compression or transposition like Phonak Sound Recover? I’m trialing the Trax 42 but am looking for a back-up plan. I read the Oticon Alta spec sheet, but didn’t see mention of it.

Thanks.

@markb said:

Hi,

Does anyone know if any Oticon products offer linear frequency compression or transposition like Phonak Sound Recover? I’m trialing the Trax 42 but am looking for a back-up plan. I read the Oticon Alta spec sheet, but didn’t see mention of it.

Thanks.

The only Oticon products that have frequency lowering are Dynamo and Sensei SP.

Hi,

I am under the impression that most posters in this thread have not read the paper. If those results can be confirmed in another study, I find this quite remarkable. There are people who suffer from tinnitus quite badly, and would be willing to try quite anything.

I would see it like this:

• your loss is aidable without loft (as has been said before)
• you are very likely to hear much better without loft
• your tinnitus might improve by the hearing aid alone, without loft and without other tinnitus features

However, if the tinnitus is really really bad and you really suffer from it, you might want to try loft even though you don´t need it for your hearing. It would be for the tinnitus only.

Just trying to keep the conversation understandable for everybody even if you’re not a statistician discussing point increases as opposed to percentage increases. Since you seemed to understand what I meant, I think I have succeeded. In explaining this to people all day every day, when I say a 90% increase, they usually look at me like I don’t know how to do math. Going from 50% to 90% looks like an improvement of “40” to most of my patients, ignoring proper terminology.

I do not claim to be an expert in tinnitus management. Not even close. Tinnitus that is THAT bothersome seems pretty rare to me, so I don’t focus much attention on it. All I have is anecdotal information about it. But here is what I have observed and here is what makes sense to me. It SEEMS like tinnitus usually seems to be most prevalent somewhere around 2.5k-3k (You can all say I’m wrong about that, and maybe I am, but this is just what it seems like). Interestingly, that is usually within the range where frequencies are lowered to. In my observation, when you amplify sound adequately in that region, tinnitus tends to be minimized. So if you are lowering other frequencies into that region, thereby increasing stimulation of that region, it stands to reason that it would likely have a positive result for the tinnitus patient.

That being said, if you are not using frequency lowering and you amplify that frequency range correctly and adequately, the same positive result can be had. So it seems like the positive result is not inherently related to the frequency lowering as much as it is the improve stimulation of that frequency range; whether with sounds that SHOULD be in that range or sounds that have been MOVED into it.

But either way, if you have tried one with no success and tinnitus is that big of a problem, why NOT try something else?