Optimal Frequencies for Speech Recognition

Hearing Loss
#1

I am 68, have a mild high frequency hearing loss, and have been using Widex Unique 330 for the past year and a half. They help quite a bit, but I still have difficulty understanding speech at times (for example when watching TV or Movies).

My question concerns an observation that I have made, both when wearing, or not wearing, my hearing aids.

If I put a finger or two behind my ears to angle them outward a bit, or ‘cup’ my hands around them, to ‘catch’ the sound, speech comprehension improves quite a bit. This is most noticeable when not wearing the aids, but also occurs when I am wearing them.

The effect here seems to be more than simply making all sounds louder, but rather reinforcing the sound frequencies that make it easier to understand speech. I don’t know this for a fact, but that’s the way it seems.

If I better understood what’s occurring here, which frequencies are the most effected, then I might be in a position to have these changes implemented in the programming for my hearing aids.

I don’t know if it is relevant, but I have very narrow ear canals on both sides, confirmed by my ENT. I have to use the smallest, narrowest domes because of this, or they are otherwise quite uncomfortable.

I have also acquired the Compass Software, and the USBLink, needed to tweak the programming of my aids, so I’m basically looking for information here to assist in these efforts, rather than just somewhat randomly making changes.

I’m just a tech kind of guy, and enjoy this type of challenge. I do understand that some may feel it inappropriate to do this type of thing.

So, if anybody has suggestions on what types of changes I might consider to ‘simulate’ what I’m hearing when I extend my ears, that would be great.

Thanks.

#2

I’m not a pro so this is just my speculation, but if it happens with the hearing aids in it sounds like they may not be turned up enough, or maybe just soft speech is not high enough. Soft sounds, medium sounds, and loud sounds can be adjusted separately so soft sounds could be turned up without making loud sounds uncomfortable.

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#3

With the advent of surround sound DD 5.1 in many tv shows and certainly movies…without a surround system, the sound gets all squashed into your one or two speakers. The music effect can thoroughly overwhelm the dialog to the point of ridiculousness. Even able-hearing people (my spouse for one) can have difficulty with picking out the dialog from all the racket.

Get a surround amp and separate out the sounds to where they belong. Then you’ll be able to pick out the dialog from the center speaker.
You don’t need 5 speakers and a sub…you can get by with 3 and no sub. You can even just use one connected to the center output and ONLY have dialog…but you’ll miss the emotion-manipulating music. :slight_smile:

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#4

Appreciate the reply. I agree that some tweaking of the programming may provide the benefit I’m looking for. I understand that the frequencies around 1500Hz to 3000Hz or so are likely important here, so I’m just wondering if anybody with more experience than I have would be able to suggest which frequencies, or range of frequencies, to play around with first.

And now that you mention it, I may recall something in the Compass software regarding soft sounds, so I’ll have to look for that as well.

#5

Thanks for the reply, and yes, you are correct that in a variety of circumstances, various movies and shows don’t have a good balance of dialogue vs sounds from whatever action is going on, such that it can often be difficult to hear what’s being said, even for someone with otherwise normal hearing.

In my situation, though, I have a fairly sophisticated Home Theater room, with what’s called 7.1.4 audio (7 channel sound: Center, Left, Right, Dolby Side L/R, Dolby Rear L/R; 1 subwoofer output, and 4 Atmos (height) channels). I have a similar but not as powerful or complex a system in our family room.

So I do have Center Channels in both systems, which contains the Dialogue. There are ways to elevate the levels of these speakers above the others, which also helps. But even with all of this, I can understand speech better using the ‘maneuvers’ I discussed in my original post.

But in more typical circumstances, I think your advice would be very important.

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#6

I normally just turn up all frequencies on the soft sound line, but I have turned up just 500 to 2500.

#7

The maneuver you mention is simply capturing and focusing the sound into your ears thereby amplifying the sound. I don’t think it has to do with frequencies. I’m sure we’ve all done that with our hands when we’re trying to hear something…from childhood on.
But I’m no expert.
Nice “sounding” system.

#8

Thanks. I’ll keep this in mind when I start playing around with this.

#9

Agreed - some type of amplification is going on. But what isn’t clear to me is whether or not this is selectively impacting certain frequencies more than others, due to the particular anatomy of my ear, canal, etc. What I’m wanting to do is emphasize those particular frequencies to aid with speech comprehension, while not also making everything else louder.

Whether this theory is correct, or if it is correct, whether or not it can be ‘simulated’ through the programming of the aid, however, remains to be seen! :grinning:

I started adapting one of the rooms in our home for Home Theater coming up on 3 years ago - the results have been so enjoyable, both in terms of how good things look, as well as how good they sound!! :grin: If only my ears weren’t 68 years old, I’d have an even greater appreciation of the full spectrum of what it’s putting out!

#10

Can’t you simply google up to find out what the speech banana on the audiogram looks like and adjust your amplification to it accordingly?

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#11

Thanks. Yes, I’ve done some googling already, so am generally aware of the frequencies involved. That chart you posted is also helpful.

I just thought I’d ask here to ‘pick the brains’ of people who perhaps have already looked into this, who might have some special insight, or specific recommendations, as a result.

#12

As you can see, the speech spectrum is fairly wide, ranging all the way from around 250 Hz up to 4-5 KHz. So amplification adjustment to improve speech clarity is not an optimal way of doing it, because you’d then pretty much have to amplify pretty much the whole spectrum. There’s no one narrow sweet spot just for speech only.

If this could be done like you think, then speech clarity is not such a tough problem after all.

The name of the game is not really to find the sweet frequencies to amplify (because there’s really none, it’s all spread out). The name of the game for speech clarity is to improve the signal to noise ratio (SNR) between the speech signal and the noise. That’s why HA mfgs have to tackle the issues in many different ways, from static noise reduction to directionality for noise blocking and better speech focus, to finding other ways to clean up the speech using dynamic noise modeling to apply noise cancellation principal to speech, etc.

So instead of focusing on trying to find a sweet spot on the frequency spectrum for speech, if you’re a DIY with self programming, try to learn all the SNR improvement techniques your hearing aid model has available, and tweak your programming around those techniques.

#13

Thanks for the insightful reply. Based on what I experienced with the ‘maneuvers’ I spoke of, and with many of the consonants up in the 2k to 4k range, I was guessing that having that narrower range would give me that slight ‘bump’ that seemed to improve intelligibility. So I will play around with those.

But your points about the SNR are well-taken, so I’ll definitely explore whatever means Widex provides to enhance things in that respect. And my initial plan was to create a separate ‘mode’ for movie watching in my main theater, and leave everything else the way my Audiologist has it set, since that environment is quite a bit different from ‘normal’ life!

Thanks again.

#14

I think the short answer to your question is that holding your hands behind your ears does two things. First it reflects more sound into your ears, or in other words increases the amplitude. Second it shields the ear from reflected sound or noise. In the absence of the noise from the back, your ear can turn up the gain more and hear better.

That brings up the question of whether or not your rear speakers in your sound system are helping or hurting. At least in theory they should be helping if the arrival time of the sound is well tuned. However these sources of sound may be competing with reflected sound from the back walls and sides of the room. Some is good because it makes the sound more open and life like, but too much can make it hard to hear. Some hearing aids have an anti echo mode that helps to reduce this effect.

Rather than just changing gains, you may want to explore using a different fitting formula or prescription. There are a number of them that should be built into the software used to set up your hearing aids. The problem however with just changing the formula is that when you change it, then you should have real ear measurements done to verify that in your ear the HA is following the set prescription. Have you had real ear measurements done? It may just be an issue of the HA not being set up properly…

#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.