K-amp to Virtue 1200's for ZCT

Hearing Aids
#1

I started wearing aids in 1994. I started with a mild hearing loss, and used aids with k-amp circuits. Other than fit, I had no trouble adjusting to them, and I’m
still using them today. They have been repaired several times. I know my hearing has gotten worse over the years, and now am told I’m between moderate and
moderately severe hearing loss. My old aids still have enough volume to blow me away.

I am having a hard time with my new Audible Virtue 1200’s. I saw one post where you recommended the audi use NAL-R program for setting
up the aids for a prior analog user. Would NAL-R apply to a k-amp aid also? I’ve been in for three adjustments, and the last time, it looked like
the program he was using was either NAL-NC1 or NAL-NL1. (I need tri-focals) The last adjustment helped some but, sudden sharp loud noises are like
cymbals going off next to my ear. The car A/C blower motor makes them cycle on and off. I can’t hear the car turn signals with them either. Loud and clear
with the k-amps.

Any ideas would be appreciated.

Thanks

#2

Wow, a K-AMP, that takes me back!

A K-AMP was a fairly early (mid 90s) Starkey compression amplifier, designed to cushion a user from loud noises. It’s too late for me to remember what the compression ratio was, but I could probably find out.

In any case as a compression amplifier you’d probably like the NAL-NL1* program best on your Destiny. That is a compression program. The NAL-R formula is linear so if you liked a K-AMP, you’d probably not like the NAL-R.

So the first thing I would do with you in run the integrated hearing test that your aids have (after I did all the regular calibration your hearing professional should have done).

This option called Audiogram in the menu on the left of the software is like a mini hearing test that measures the threshold of your hearing. But the test also offers a ULL test, that measures the loudest sounds you want to tolerate. What you are left with is called your dynamic range, the actual hearing you have left at each frequency from quietest to loudest.

By running this test properly at every frequency the software and therefore the aids will have a very good idea as to where you’d like the sound to be.

As for aids cycling on and off, you can adjust the attack and release time. To make them more or less sensitive to sound and make them react quicker or slower.

Those would be my first suggestions. Other than that it would be a matter of me sitting down in front of you and figuring things out. It’s hard to verbalize everything I’d do without seeing a patient, the audiogram, the settings currently in the aids, and a variety of other factors.

But the hearing test idea, that would make a lot of difference, because the software takes a lot of the guesswork out of it.

#3

OK, ZCT, thank you for the help. They extended the return period for me so I’ll give them a couple of more adjustments.

One thing I never have understood is why anyone would not want loud sounds cushioned. Unless one was deaf in that frequency, why would they want the sound of a fire truck siren magnified?

#4

I have had some previous users who did not like the loud sounds being reduced much, as it made things sound muffled to them (their previous aids did not have as much compression). It all depends on your particular hearing loss and preferences.

#5

It’s all about your dynamic range. Take one frequency of sound, say 1000Hz. With normal hearing my dynamic range is probably about 0dBHL - 110dBHL. Yours could be 30dBHL-100dBHL. So thus your range of hearing at that frequency is less than mine. You still want all the same sound information as I do, but you want it squeezed into a smaller range.

The problem that many people don’t realize is that often, when their hearing gets worse, it’s not just the threshold (quiet noises) that change, but sensitivity to loud sounds alter too. So often a person can have a hearing loss, but also be far more susceptible to finding loud noises uncomfortable than someone with perfect hearing.

It seems counter intuitive. You’d think that a hard of hearing person would welcome louder sounds, it almost seems like common sense. But due to some of the hair cells in the inner ear providing less protection from loud noises, often hard of hearing people can be more sensitive to loud noises.

So a modern hearing aid tries to take into account the dynamic range at all frequencies. That’s the beauty of the test I recommended you take. It will teach the hearing aid what is acceptable to you and what is not. Without programming this information there is no way the hearing aids can ‘know’ what you like and what you don’t like.

#6

Thanks for the addition information, ZCT. I have always been bothered by loud noises. I guess I just assumed everyone was.

I go back in for adjustments next Thursday. I’ll report back afterwards.

Audiogal, thank you for your input also.

I found this K-AMP information at Etymotic Research, Inc.: http://www.etymotic.com/ha/kamp-faq.aspx

I think this information is about 5 years old so things may of changed since then.

Frequently Asked Questions

Q What Do K-AMP Hearing Aids Do?

A K-AMP circuits offer level-dependent progressive frequency response (greater treble boost for quiet sounds). When the K-AMP circuit was introduced in 1989, it was (and still is) the only amplifier that combines wide dynamic range compression (WDRC) with the following features: Variable recovery time which provides instant recovery from hand claps and door slams, and slow recovery for normal sounds to eliminate pumping.

A single-channel circuit that performs like a multi-band compressor. In the original K-AMP circuit (TILL version) there is a compression ratio of 1.3:1 in the low frequencies and a compression ratio of 2.1:1 in the highs. The programmable K-AMP can be programmed up to 3:1 in the highs.

Clean, undistorted operation even at inputs up to 110 dB SPL. At 90 dB SPL input, the K-AMP has essentially zero-noise and zero-distortion out to 13 kHz (a coherence of 1.0). No other circuit can make this claim.

Q What Is The Difference Between K-AMP WDRC and Other WDRC?

A In order to determine how much gain to provide, all compressors require a level-detection circuit. The K-AMP uses rms detection, which provides a more accurate estimate of signal energy (loudness) than either peak detection or average detection used in other circuits.

#7

Hi Fred, ZCT and others:
I have tried like 7 visits these past two months for my Destiny 1200 adjustments. Now my dispenser stick to the NL1* settings and set the low frequency kneepoint to 48, 50 for high freq. The sound is better but still not as good as my Beltone. I wonder whether by making the tubing longer so that HA is closer to my ear drum can help make the speech clearer and louder. I still haven’t asked my dispenser to do the threshold and ULL test for me, but I think my settings right now is pretty much my dynamic range.

Paul

#8

Paul,

Have you tried the KP a little higher still? It may give you a little more punch that you seem to want.

#9

Hi ZCT:
Actually the kneepoint for low frequency was at 44 before and I have changed it to 48 and I found it was a little bit too loud. I wanted it back to 44. Therefore, I think the my comfortable kneepoint is 44 and 50 for low and high freq. What other method do you think can improve the speech clarity and volume?
Will longer tubing work?

Thanks
Paul

#10

Well, I spent two hours with the HIS yesterday. He used Inspire 3.0 for the first time, and set the compression
ratios to the same as the k-amp aid specs. 1.3:1 for lows, and 2.1:1 for highs. He also made the attack time faster. Then ran
them through the audiogram check. All seemed well, sudden loud sounds were being cushioned, instead of blowing my
eardrums out. Afterwards, I walked around some loud machinery with no problems. I could hear the turn signals in the car.
The A/C blower motor didn’t make the aids cycle on and off like before.

When I got home and turned on the TV, all the voices had lisps. Radio, stereo, ditto. I wasn’t around enough human voices to judge
how they will work there. I’ll do that today.

I’m starting to think digital still has some bugs that need ironing out.

There is a very detailed article that explains my original complaint of loud sounds here: Understanding Transitions

A 2 year old article comparing aids here:http://www.hometheaterhifi.com/volume_13_2/hearing-aids-6-2006-part-6.html

I realize this post gives the Audies & HIS’s here very little information to make a diagnosis with, so at this time, I’m not asking for one. I’ll follow up in a week or so.

#11

How about increasing the kneepoint and lowering the output limit? This would make quieter sounds louder, but still place an upper limit on all sounds.

And trying longer tubing would not be a problem if you want.

#12

Well, I returned the aids last week. I decided that whatever advantages the 1200’s would give me over my old aids would be very slight, and would not justify their higher cost. The last adjustment (see my last post) did help with dampening loud noises, but, it also seemed to reduce power. Not to mention making other peoples voices unintelligible. While I’m sure the bugs could of eventually been worked out, I just didn’t feel that this pair of 1200’s would ever be set up to be much better than my old analogs. Maybe with a different dispenser things would have gone better. Another thing, I never found a post here or anywhere else where anyone mentioned how happy they were with their 1200’s.

I may try AmericaHears, Hearsource, or I might just have another pair of analogs made to my latest audiogram. One thing that bothers me about AmericaHears and Hearsource is they give out zero specs on their own aids. They describe all the features, but, they give no specs. I’m probably too picky, but I like to know what’s under the hood.

Fred

#13

having specs, makes the process of comparing apples to apples easy…
I agree, specs should be publish …

#14

Here are some specs on the aids.

http://www.americahears.com/tech/ADSIE.pdf

You can read about the processor chip here:
http://www.sounddesigntechnologies.com/

And the ADRO technology here:
http://www.dynamichearing.com.au/

#15

32 channels in a instrument which has a 250hz to 8000Hz doesnt seem
efficient…

#16

1000$ is a real good price

#17

Please explain in more detail for us layman.

Thank you,
Mike

#18

the specs says 32 channels, you only have so many frequencies between 250 and 8000hz right, perhaps, your audi or His measures only–
250, 500, 750,1000, 1500, 2000, 3000, 4000, 6000 and 8000, so technically
you have have 10 datapoints in the audiogram… so that leave us say with 22 channels- I wonder do you have a gain handle for 32 channels? if so that seems cumbersome right?

#19

This is a wild guess on my part. I would say 4 memories for each aid with 8 channels or frequency settings for each memory.

#20

Actually the 32 channels is a nice feature and very useful. The user only has 9 bands (where each band would cover several of the 32 channels) to adjust when using the software, from 250Hz to 6000Hz. But this is not how the 32 channels are used. The noise suppression algorithm identifies the frequencies of the noise and will adjust only the frequencies that pertain to that noise. So for example, there might be running water at 300Hz and it will bring down 300Hz while leaving 250 and 350 alone. This ability to be very selective about the frequencies during dynamic adjustment insures that the noise is reduced while leaving other frequencies alone.