There is a lot of confusion in the hearing aid industry relating to channels and bands. Simply put, channels affect how the hearing aid operates; bands affect how the hearing aid is adjusted. In general, having more channels is better than having more bands, and the more channels the better – to a point! Research has shown that more than eight channels offers marginal improvement. More important than the actual number of channels or bands is what the hearing aid is doing with them. In other words, don’t place too much emphasis on these numbers. The more noise you regularly experience, the more you will benefit from a greater number of channels and bands.
Channels are sections or slices of the frequency spectrum that are processed more or less independently by the hearing aid. For example, if a hearing aid has eight channels, it will divide up the sound into eight separate sections and each section can be processed independently from the other seven. This is useful for automatically adjusting to a variety of sound environments. Usually the audiologist or hearing specialist can make some changes to the channels for the management of loud sounds.
Bands are used to adjust the hearing aid’s amplification characteristics and for fine-tuning the hearing aid to the wearer’s loss and preferences. Hearing aids can have a band for each channel or multiple bands per channel. Like channels, the audiologist or hearing specialist can adjust these bands to the wearer’s preference.
Experts say 4 to 6 channels will take care of all but a few .
There are several down sides to more channels such as increased process time, slightly more phase and harmonic/intermodulation distortion. For all but a tiny minority of HOH, aids with 12-20 channels provide no measurable benefit over lesser channel models.
And if you think your professional is going to take the time to carefully program and evaluate each of the twenty channels individually you must believe in the @#$^%&.
Noise reducing BANDS are another story altogether. In a few cases notching out a narrow band source of noise is very usefull in special situations.
Though expensive models with lots of channels often include marginally useful bells and whistles. IMO Ed
Many of the useful advanced features, though are only available on the aids with more channels. So while more channels are not necessarily that useful, you may need to choose an aid with more channels to get the most advanced feedback suppression, for instance.
Experts say 4 to 6 channels will take care of all but a few HOH.
It depends how you define take care of.
It is very important to remember that these days 2-4 channels are reserved for some of the most basic hearing aids available. Even six is considered barely mid range.
The problem with this discussion is that you are taking a hearing aid and observing it in a vacuum. In the REAL world the number of channels and bands on a hearing aid are not the only thing that changes between models. Very advanced features are usually tied in to the model. So one typically cannot choose to buy a hearing aid where the only difference between the models is the number of channels and/or bands they have.
In car terms, I can buy a BMW 328i which this year has a 240HP four cylinder engine in it. Or I can buy the BMW 335i which this year has a 300HP engine. So the difference is 60HP right? WRONG! A whole host of things get changed between these two models that affect not only the cosmetics of the vehicle but the performance, ride and handling. Features that are optional extras on the cheaper 328i are standard and included on the 335i. So it isn’t simply the argument about whether 60HP turns it into the ultimate driving machine, the question is how do the other changes affect the vehicle performance and your enjoyment of that.
There are several down sides to more channels such as increased process time, slightly more phase and harmonic/intermodulation distortion. For all but a tiny minority of HOH, aids with 12-20 channels provide no measurable benefit over lesser channel models.
That simply isn’t true, it’s opinion presented as fact. Some of the chief research audiologists at Starkey found that in fact they could measure additional benefits up to 16 channels. True there was a law of diminishing returns, beyond 8. And of course it wholly depends on what it is you are listening to and the type of hearing loss you have.
And if you think your professional is going to take the time to carefully program and evaluate each of the twenty channels individually you must believe in the @#$^%&.
Since when does that happen? Modern hearing aids are set automatically using an advanced fitting formula. It can be fine tuned with various tools including as an example insitu-audiometry, where the computer makes the adjustments based on the available data. Then the hearing professional can fine tune from there.
Though expensive models with lots of channels often include marginally useful bells and whistles. IMO Ed
Honestly Ed, if I could take you to one of my clinics, I’d love to show you how you are completely wrong. But trust me I have taken hundreds of patients who have significant experience with hearing aids, and shown them first hand how modern technology can improve their situation. I’ve had people tell me that they have not heard as well as I have shown them in over a decade.
There are some hugely beneficial features on higher end aids including hearing aid communication to integrate background noise filters, frequency transposition, and a host of highly adaptive filtering systems to reduce listening effort and provide a more natural sound in a wider variety of situations.
So to call advanced hearing aid features of marginal use is simply ludicrous.
In general, having more channels is better than having more bands, and the more channels the better – to a point! Research has shown that more than eight channels offers marginal improvement.
It depends on the researcher and on what they are testing for. Are we talking speech in silence, word lists, sentences, speech in noise?
I don’t think that research has ever categorically concluded and been universally accepted that all hearing aids in all situations provide only marginal improvement beyond eight channels.
Furthermore as I mentioned before, it is rare to ever find that the number of channels/bands are the only difference as you go from one hearing aid model to another. It is almost always the case that in addition to there being a difference number of channels or bands, other features are added or subtracted as you move up or down the price list. And those features can make all the difference in the world to many people.
I do however agree that some cheaper manufacturers seem to be in an ‘arms race’ advertising absurd numbers of channels on their hearing aids. And in that case a trade off is surely being made between channels for the sake of channels and actual effective hearing improvement.
Let’s see now what in technical terms is changed when we go to more channels.
A channel usually allows control in channel gain and compression parameters. More channels means each channel controls a smaller chunk of usuable spectrum.
So if we have a specific hair cell that is not normal and either is producing weak responce and/ or distorted responce at certain input freq/level we can adjust and eliminate the problem.
So the theory of the benefit of more channels is that control is better achieved by a more narrow band width control and that narrow control is better because it does not affect adjacent cells. But the pathology of compromised hearing is almost always accompanied by loss of cell selectivity (a lack of sharp selectivity) low Q in electrical terms).
Hence the benefit of more and sharper channels is not always real. Ed who sees with an engineer’s eyes. Am I missing something?
What this industry needs is something like the Consumer Reports organization.
I am not aware of any independent and unbiased source of verifiable scientific level information on the real world effectiveness of channels. bands, or features. What’s out there is self serving opinion for the most part.
What this industry needs is something like the Consumer Reports organization.
I am not aware of any independent and unbiased source of verifiable scientific level information on the real world effectiveness of channels. bands, or features. What’s out there is self serving opinion for the most part.
Just my personal opinion, Ed
You are right, that is what is needed. But based upon my admittedly short experience as a consumer, I seriously doubt that anyone in the industry wants that. The consumer right now is completely beholden to the various sellers of hearing aids and the less information that is out there for the consumer, the better it is for the bottom line of the manufacturers and the resellers. The pros can shout all they want about being health care professionals, but nearly every professional that I have met is simply trying to sell the most expensive hearing aid that they can. They may come up with a million reasons why that one is the one you should buy, but the bottom line is the bottom line - and the bigger the sale the higher the profit.
An accessible source of objective information for the consumer will significantly impact the way these devices are sold, and I don’t think the industry wants that. I would love to be wrong about this, but nothing I have seen thus far suggests otherwise.
Central Virginia