Optimal Frequencies for Speech Recognition

Hearing Loss
#15

An interesting reply, Sierra.

With your post, and the other discussing directionality, it does make me wonder what the impact is of those rear speakers. It raises the possibility that by having the programming accentuate the dialogue coming from the front, I might lose some of the immersive effect coming from the sides and rear (and above, from the Atmos speakers).

The Marantz AVR I have does included what’s called 'Audyssey XT 32" where you plug in their microphone, and it adjusts timing, frequency response, etc., to at least theoretically optimize its performance for one’s particular room, and should address the valid concerns about this you mention in your post.

But as you point out, the basic room acoustics and reflectivity can be an issue beyond this, and many opt for a wide variety of room treatments to better control these factors.

And if by “real ear measurements” you mean having the Audiologist do a kind of audiogram with the hearing aids in my ear, to test out ‘real-world’ performance, rather than just in the isolation box without the hearing aids, then yes, this is something that he did. If I remember right, this is called ‘Sonogram’ in the Compass software.

He is a good guy, and an experienced Audiologist, and I am reasonably confident that he is doing a good job. My desire for DIY tweaking is not from thinking it’s something he can’t or won’t do, but more that there is just no practical way in an office setting to play around with a variety of settings, nor assess their real-world impact in my home environment.

Can you elaborate on what you mean by “different fitting formula”?

Thanks again.

#16

I have found that wearing ITE custom hearing aids is my answer, I have had one pair of behind the ear aids that were really good aids but I had more issues with noise and speech recognition than I do with my in the ear aids. The sounds are more natural with the in the ear aids too me also.

#17

I think Sierra is on to it. You have all these speakers producing some sound. You cupping your ears lets your ears focus more on what’s coming out the front which is usually the center speaker. This would be the same for normal hearing and aided or not.

#18

Real Ear Measurements are when a small microphone is put into the ear canal first and then the hearing aid. They are used to measure what the HA receivers actually produce for sound levels, and then the audiologist should adjust the gain to match the sound level target. Here is a video that goes into the full detail of it.

The sound level target is set by the formula used for the fitting. The common standard one is the NAL-NL2 standard, but there are other options, including proprietary ones from your hearing aid manufacturer. They vary in the amount of gain and compression applied vs frequency. Here is an article that talks about them.

#19

The newest software to fit hearing aids can automatically do the REM test. When my Audi at the VA setup up my aids he set up the REM test than the software on the computer did the rest

#20

Yes, here is a description of how the Signia Connexx software does it.

#21

You are making a choice to provide a bad hearing environment so unless you prioritize speech in your sound system you will always be making it difficult. Immersive sound is great, but the movie was designed to use wide dynamic range and audio coming from all around you (direct or reflected). In the speech band are also a lot of effects since many effects are broad spectrum. Unless you substantially bring up the level of the center front (or wherever the bulk of the dialog is) compared to the other channels then I think you are living with a bit of denial. Perhaps one day we’ll have selective audio channels in a movie where the dialog can be accentuated in the mix.

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#22

Yes, the programming software can incorporate/integrate the REM test in it so that the professional wouldn’t have to use their own REM software. BUT, they still need to have the physical hardware equipment to perform the REM test, even if the software is now integrated. Because of that, a DIY like the OP won’t be able to perform the REM test himself without the physical hardware for REM.

That’s the issue with DIY. Without being able to do the REM, any major tinkering, especially with fitting changes or things that will cause a re-prescription on the hearing aid to the new change, will undo the REM adjustment that was done the last time.

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#23

So true, when my Audi did the set up the first time and even the second visit he did the REM test twice each time. His comment was better safe than sorry. He seemed to follow the old saying take the time to do it right the first time and it will mean less time spent in the long run. Even when he set up my music and nature programs he spend long than anyone else had ever doing checks

#24

He’s talking about the fitting rationales available to use for amplification prescription. These fitting rationales uses various compression rates at different frequency points and different input sound levels with your hearing loss at those frequency points as an input parameter to determine the proper level of amplification for you hearing loss at a particular hearing frequency and input level.

There are standard fitting rationales like the NAL-NL1, NAL-NL2, DSL, for adult, and DSL for pediatric prescription. Then HA mfgs may have custom proprietary fitting rationales of their own that they prefer to use because they believe it’s best fitted for their hearing aid design as well.

Although you should probably start out using the HA mfg’s proprietary fitting rationale, but if you are still not happy with it, then you can try some of the standard ones to see if you may like those better or not. Some people who are used to a certain fitting rationale over time may tend to prefer to stick with that rationale going forward if they like it better than something new to them.

#25

For what it is worth, I will go in for fitting this week, and I plan to ask for a specific program to watch TV. My system is a 5.1 with rear speakers, but nothing elaborate. What I will ask for is a fixed fairly narrow front microphone focus that reduces sound from the sides and the rear. That way I think I will hear better without compromising the sound that others without hearing loss will have. I should only hear the left, right, centre, and sub-woofer speakers. My hope is that it will have an effect similar to cupping your ears!

#26

They call it Directional Adaptive for the Television program in Connexx for the Rexton KS7’s.
But there’s not really a whole lot of sound that comes out the back speakers. Just environmental ambience sounds or sounds visually moving towards the back. iirc

#27

z10user2:
The TV should have the option, in its sound settings, to choose between surround sound and ordinary stereo.

#28

Agreed. The tv or the STB. But all that sound from the delivered surround sound is getting crushed down into just those speakers and so it becomes a giant mix of sound. Whereas splitting the particular speaker sounds out as delivered leaves the center with just the dialog.

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#29

I very much appreciate all the knowledgeable replies here. They have been very helpful, and this is why I posted here. A few comments:

Regarding REM, this is how Widex describes the ‘Sensogram’ function in their Compass GPS fitting software:

The Sensogram is an in-situ threshold measurement and one of the most accurate ways of fitting a hearing aid. The measured in-situ thresholds take into account the effect of the earmold/shell, the size of the individual ear canal and the hearing loss.

I don’t know if this serves the same function as REM, but I do know that this was done during my most recent fitting session.

And I agree, that my theater environment is a particularly challenging one. Add to this the fact that the quality and audbility of the dialogue tracks will vary quite a bit from movie to movie, and I realize the inherent difficulties here.

To provide some perspective, the problem I have in understanding dialogue in most movies is not severe, and overall I am quite pleased with the improvement my current aids and fitting provide. I guess I’m just basically wanting to put a little icing on an already delicious cake.

So I don’t feel that I need to reinvent the wheel with regard to my current fitting, but am just curious if a few minor tweaks could add those few extra percentage points of improvement.

I think my initial plan will be to create a new programming slot for movies, with the same settings as what I currently have, and just modify the directionality parameters, to emphasize the front, and de-emphasize rear, and the sides. I do specifically recall him pointing out those options when we did the re-fitting last week, so I know that should be fairly easy to do.

Depending on how that works out, I might explore some of the other options suggested here.

Thanks again to all who have posted their ideas and comments, which I have found very helpful and instructive.

#30

In-situ audiometry is not the same as REM. It’s more like generating an audiogram using the hearing aids and the fitting you have instead of doing it with external (calibrated) equipments in a quiet sound booth.

There is an advantage to using the actual hearing aids with the actual fittings to retest your hearing thresholds again because if your hearing aids is underperforming (under amplifying), then there’d be some implicit correction built into the test to bring it up to par. But you just don’t know if it’s the hearing aid that’s underperforming or if your hearing has worsened, or if the equipments in the sound booth for the original audiogram is not calibrated.

If there’s a difference between the in-situ result and the sound booth result, you simply just chalk it up to unknown factors and move on with re-prescribing based on the new in-situ result. If they match closely, then it’s a good indication that maybe your hearing loss hasn’t changed in between the tests, and the sound booth equipment and the hearing aids are calibrated and performing on par with each other.

But the in-situ test is still about threshold testing, which is different from the REM because the REM is not about threshold detection testing. They’re two different kinds of test.

But lacking the option of being able to do REM every time you change your fitting or programming because you’re a DIY and don’t have access to REM equipments, I guess you can view the in-situ audiometry as a poor-man version of some kind of testing that’s still better than not having any kind of testing at all.

#31

While this seems to make sense, you’d have to remember that by doing so, all you’re reducing is the sound coming from the two rear speakers. I’d imagine that most programs won’t send much sound to the 2 rear speakers, not to the point of crowding out the sound from the front center speaker anyway. And if a movie actually sends sounds to the 2 rear speakers for special effect on actions like car chase, chaos in the environment, etc, you’re probably going to want to hear the (occasional) sounds from the two rear speakers for full movie effect.

The bottom line is that I’m not sure if adjusting the directional focus of your hearing aids to the front area speakers only will give you THAT much speech clarity improvement, all the while you’ll end up cheating yourself of the occasional special effect sounds coming from the rear speakers. I use the surround sound 5.1 setup, too, and I just don’t find the 2 rear speakers to really occupy the sound space that much to become a noise issue in the first place.

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#32

@cvkemp in the other OPN 1 ITE thread made a comment that I think would apply well to your case. Instead of trying to tweak your setting to hear speech better in your surround sound setup, just get a TV streamer for your hearing aids, then listen to both the streaming material (which should help make speech clearer) and the regular surround sound speakers through the hearing aids’ mics simultaneously. This way, you can even watch the movie with somebody else and get a little extra something streamed to your hearing aids to hear speech better. The 2 volumes (streaming and mics) should be independently adjustable.

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#33

Thanks for the detailed explanation.

If nothing else, I will ask my Audiologist about REM, and why and when he would use this (assuming he has the technical option of doing it).

#34

Understood.

In my Theater room, there can be quite a bit of sound coming from the Rear, and as others have also pointed out, there may be echoes through the room as well, which could contribute to the problem.

Also, the fact that I have a Dolby 7.1, vs Dolby 5.1, could play into this as well, in terms of speaker placement and activity.

In any case, there’s nothing to be lost by creating a separate program that’s identical to my primary one, and modify the directionality to see what it does or doesn’t do.