AB's HiRes strategy vs. Cochlears program strategy

[Guest guest]

Hi Mike

Great post but can I clarify some things you wrote about the AB

device. I hope you don't mind and if you do please feel free to let

me know. I just wanted to share from an AB user prespective on this

one, Hi Resultion is NOT anything like CIS!

AB has the following strategies available for their current 90K

users -

CIS

Hi Res P

Hi Res S

MPS

CIS (Clarion, Med-El, N22, N24): CIS because its probably the most

straightforward. Basically, it uses the same set of 6-8 electrodes

(any

additional ones available are simply not used) and fires them in

sequence (one after the other) to deliver sound to different parts

of the cochlea in a way that reflects the original sound signal.

It's stimulation rate can be as high as 20,000 pulses per second,

depending on the device. Med-El uses what it calls " CIS+ " , which is

effectively is CIS with a slightly enhanced processing algorithm.

CIS stands for Continuous Interleaved Sampler.

SAS (Clarion only): Fires all of the electrodes simultaneously,

which is how sound is delivered in the normal ear (to all parts of

the cochlea at once). The advantages of this is that this more

closely resembles how sound is delivered in the normal ear, and more

sound information can be transmitted with each sweep of the cochlea

(up to 100,000 updates of sound per second). The disadvantage is

that the stimulation from one electrode can interfere with the

stimulation from another, in what is known as " channel interaction. "

The Clarion HiFocus electrode was designed to minimize channel

interaction dramatically, but not eliminate it altogether. SAS uses

bipolar simulation (i.e it pairs electrodes for stimulation) and

thus uses 16 electrodes to deliver 8 channels. SAS stands for

Simultaneous Analog Stimulation.

MPS (Clarion only): This is a hybrid between CIS and SAS, in an

attempt to gain some of the theoretical benefits of SAS without the

drawbacks of channel interaction. In MPS, two electrodes or more are

stimulated simultaneously, but they are far enough apart so as not

to experience channel interaction. Like SAS, MPS uses bipolar

stimulation and so uses 16 electrodes to deliver 8 channels. MPS is

also sometimes known as " PPS " .

SPEAK and n-of-m (N22, N24): The theory behind SPEAK (also called n-

of-m) speech strategies is to accentuate the strongest sound

frequencies (spectral maxima) and repress others, in an attempt to

bring out the most pertinent sound clues necessary to understand

speech. It does this by selecting a different set of up to 8

electrodes with each sweep of the electrode array. This may be

particularly helpful in places where there is a lot of background

noise, but the drawback of this is that it is confined to a

relatively slow stimulation rate and, by accentuating certain

frequencies over others, it is a deliberate distortion of the

original sound signal. An experimental form of n-of-m has been

tried with Clarion by independent researchers, who reported

promising results. SPEAK is short for for " Spectral PEAK

extraction " .

ACE (N24 only): ACE is a hybrid between CIS and SPEAK, much like MPS

is a hybrid between CIS and SAS. ACE combines the higher

stimulation rate of CIS with the way SPEAK highlights certain

frequencies. Typically, with each sweep of the electrode array, ACE

activates between 6-12 electrodes out of 22 available ones. ACE

stands for Advanced Combination Encoders.

High Resolution (Clarion CII and 90K only): This is a strategy that

uses higher stimulation rates than have ever been possible with any

implant, and more channels than the previous generation Clarion

device.

On top of all the differences in speech strategies, there is

obviously the individualized customization and optimization that the

audiologist goes through with each person. For instance, the exact

stimulation rate or number of electrodes used may vary to some

degree.

Kim B

Advanced Bionics CI

>

> Hi Bill, & Every1,

>

> This is a very difficult question and one I have tried to answer

for

> myself for over a year and to be honest I have read all about the

> various differences (and there are lots) but I can/will not say I

see

> one as better or superiour to another. Quite frankly much of the

> information published by the manufacturers is so technical it does

> not explain things very plainly. Truthfully I find it extremely

hard

> to compare AB and Cochlear and I believe it is impossible to

compare

> them fairly they both acomplish what they are designed to do, but

> they do it very differently. I understand Cochlear better because

> that is what I use and have written a few posts attempting to

explain

> the programs speeds & options in plain english - I will be happy

to

> send those to you seperately if you would like.

>

> I know this is not really much help but as I state I don't beleive

> fair comparison is truly possible, I will list a few things -

> keep in mind I am not saying better or worse here just different.

>

> Cochlear;

> 4 programing stratagies CIS, Speak, ACE, Hi ACE.

> Speeds from 250hz to 3500hz (capabile of faster speeds however

> testing showed no benefit with higher rates for majority of users

and

> generally speaking slower rates are prefered by most users of

> Cochlear brand implants/processors)

>

> Advanced Bionics;

> ***My Understanding ONLY*** 2 programing Stratagies. Hi Res, SAS.

> Hi Res is a modified version of the original CIS strategy AB has

done

> some wonderful things with this particularly in improving speed

and

> music perception as reported by many users. I have read that SAS

is

> not used much any longer and was not as popular with users (I do

> not know how accurate that is but I never see it mentioned in any

of

> the forums or message boards so it leads me to believe Hi Res is

the

> prefered strategy). AB will soon release their new 120 Channel

> strategy which Kim mentioned, this does sound very exciting and

from

> what I have read is a big advance but I do not know much about it

yet.

>

> Speeds with the AB Strategies are up to 90khz (I am not sure what

the

> lowest speed is but I suspect it is comparable to Cochlear)

>

> Just to illistrate my point about the difficulty comparing I was

> discussing speeds with my Audi one day and she did a somewhat

> informal check of her patients and determined almost without

> exception AB users prefer Higher speeds and Cochlear users like

> slower speeds, her conclusion the brands are different not beter

> best - just different! The only comparison she would make is the

> results between the 2 brands are almost equal (she will never say

> exactally equal or if one is slightly better just " Almost "

> equal...lol)

>

> I guess it is much easier to compare the physical features and

> options, and for me that was what it came down to. I guess this is

> somewhat easier for me to understand but even though there are

> differences both are good, and overall neither are bad. I think

like

> Carol stated for these it is a life style choice, if you need to

rate

> the features compare them to your life style - what is perfect for

me

> may be awful for you. Batteries are the most often compared, for

me

> the convenience and avaliability of 675 button cells is what I

want,

> for anyone with kids or who might have problems with the small

> batteries (arthritis etc) the AB rechargable is a good choice.

>

> I guess the last thing I will add is you often hear people speak

> about future enhancements and upgrades, well both AB & Cochlear

score

> very well in that dept, as a matter of fact the internal implants

are

> built with great capacity than is needed to allow for upgrades as

has

> been shown in the past. Examples are easy to look at the orignal

N22

> Implant users were upgraded to the 3g BTE processor from the older

> Body worn, the Original N24 Implant users will sonn be able to use

> the newest Freedom (which will also be released for the older N22

> after that). The story is simular for AB although I can't quote

you

> models but I know they have built in extra capacity to the

internal

> implants and upgraded older implant users to new processors as

they

> became available.

>

> I am sorry for the longggg post and I do hope there is some useful

> information in all this, but it is a difficult topic and I feel

there

> is not " Right " or " Wrong " answer just personal or life style

> preferences, and if anyone see anything I inaccurate in the above

> please tell me I will be happy to edit the content.

>

> Regards,

> Mike " Ears Hopin " P

> Nucleus Freedom

> Implanted June 3rd/05

> Activated July 6th/05

>