Compression & other features in hearing aid?

Edit: Don’t know if it matters, but I moved this post from the general Hearing Aid category to DIY

Is compression a feature that can be turned off and on? If so, I’m thinking maybe it’s called by different names by different companies. I’m looking for it for my Philips 9030 and have attached a screenshot of the features screen. Are any of these compression?

I’ve ordered an Intro to Audiology book that was suggested on this forum and depending on how my fitting tweaking session goes later this week may order the Noahlink Wireless and begin DIYing.

Both @Um_Bongo and @Neville recommended that one way to deal with the issues I’m having is to build up from a basic program that includes little or no automatic processing, just volume control. But, I don’t see how I can do that without doing it myself. Seems like it would take many, many small tweaks and tries. I have a Music program. I don’t know what underlying processing is going on but the changeable features (those in the screenshot and frequency lowering) are all off or set to min (I think. It’s whatever the default is). Presumably I could DIY test and fit with this program. For now though, I’d like to know what the current compression settings are.

If this is better suited to the DIY part of the forum, I’ll re-post.

Compression refers to how the hearing aid handles the loudness of sounds and is a basic function of all modern hearing aids. You can find much more comprehensive explanations elsewhere, but basically hearing aids apply different levels of gain to an input sound depending on how loud it is. If they didn’t do this then you’d either have loud sounds blow out your eardrums or soft sounds that weren’t loud enough, depending on what fixed gain you set. The hearing aid’s job is to “compress” the full 120+ dB range that people with normal hearing have into a range that you can hear, without damaging your hearing further. The more significant your hearing loss, the more compression is needed, but you don’t want too much or you won’t be able to tell the difference between loud and soft sounds.

Further reading

Thank you for the explanation, but I’m looking for where/how this is handled in hearing aids as I’ve been told by hearing professionals that this is one of the processes I might want to do something with to figure out what fitting configuration is going to work for me.

Maybe it’s just built into the manufacture of the aid and can’t be changed, but that’s not the impression I have from exchanges on this forum.

I would suggest trying
The courses are all free and very helpful for us that are new to adjusting our own aids.
My believe my aids, Resound One’s, with SmartFit software use an adjustment labeled, Environmental Optimizer II to help control the balance between loud and soft levels.


You’ll need the actual fitting software that the audiologist uses to adjust compression. It’s not an on or off thing, but you can create a more “linear” sound."

Thanks. I downloaded the software, which is where my screenshot comes from. I know I can’t actually hook it up to my aids without Noahlink Wireless, but I want to understand what all the features are and which of them are related to compression. After skimming the Wikipedia entry provided in a previous post I suspect more than one of the features in the screenshot are compression in some form.

Perhaps you would have better luck posting a diy oriented question under the diy category?


If you actually have the software, input an audiogram and find the fitting curves. In one view of the fitting curves there should be a way to modify compression ratios.

1 Like

What does the fit instrument screens look like?. Choosing different programming rationale fitting formulas apply different degrees of compression. Also some software allows you to choose semi linear and linear setting which changes the compression. Looks like the feature section is for the additional features of the hearing aid. Look at the fit instrument section.

1 Like

Here’s the screen image under Fitting Instrument. I see Frequency Lowering as a menu item on the top bar, but I’m not seeing anything on the screens under those menus that uses the word compression.

On this screen under Fine Tuning I see the abbreviation CR just above the grid of fitting numbers under the left ear graph, left side. But if that stands for compression ratio, (per @MDB post) I don’t know what it’s referring to.

1 Like

Thanks for the screen shots. CR is compression ratio. Not sure where you would find the compression ratio number on your software, But some software list the CR for each frequency. On mine the compression is in the range of 1:1.3 to 1:1.7 across the frequencies. If you click on the CR does it give you the CR numbers?

No, the CR on the screen is just a label. Thanks for your help. I’ll hunt around and see if I can find any other instructions or info online specific to the Philips 9030. I already have these two below, but not seeing the answer I’m looking for in them.

@PVC I found a couple of sets of fitting instructions for the Philips 9030 if you’d like to include them in the DIY school pdfs. This one is useful in that it gives a short description of what each additional feature is and a few tips for what to do given particular complaints the wearer might have.

This link is to a Philips fitting manual. I didn’t find it very useful since essentially what it says is open the software and follow the steps on the screen. But there’s some setup stuff at the beginning and the document is in multiple languages, so might be useful to someone.

1 Like

At present time I am frying-bigger-fish and have not yet started on secondary brands. But I will have a look and see where it might fit. Thanks for the heads-up.

Just to add to what I’m finding in case someone else is ever hunting for info, this white paper talks about compression in the Philips–much of which is built in. It says there are two basic settings that can be turned off/on, but I’m not seeing it in the software. By default it says the designated method is based on the wearer’s age and level of hearing loss. There’s another compression function specifically to deal with speech-in-noise (in some models) that supposedly also can be turned off/on and its sensitivity adjusted. Maybe these only appear as options once a hearing aid has been detected, because I’m just not seeing them in the software screens. But it gives me something to ask the fitter about!

Look for a Simulate feature. I’m not very familiar with Philips fitting software but many fitting software programs have a Simulate feature. Phonak Target has a training session.

You select a client (Joe Blow) and then start a simulate/training session and it lets you practice using all the features without connecting your hearing aids;

1 Like

I’m afraid that is true.
Philips is similar to Oticon, and compression ratios are not user adjustable.
I spoke to an Oticon rep regarding that issue, and the reply was: “The fitting software adjusts the CR based on the soft, medium, and loud gain knee points you select .”
What’s frustrating, is we have no control, it’s all software dependent.
Change the fitting rationale, and CR changes.
Change gain controls, and CR changes.
Change sound controls, and CR changes.
I haven’t looked at Phonak Target, but I do believe it allows CR adjustments.
@tenkan , @Zebras , or @MDB would prolly know.

The key is, a really professional AuD, that knows the product, can adjust the settings to properly set the CR for your needs.
Good luck!

1 Like

Sorry I can’t be of much help on this one, I believe you are correct @flashb1024
These are more like the Sonic from Demant A/S then any particular Oticon models.

Thanks. This is unfortunate. I found a Whitepaper on the Philips Hearlink that made me think there are some compression adjustments possible, but it turns out those are on the 9010, not the newer 9030. More automation there. I just finished a remote fitting adjustment with Costco and I asked about the CR label in the screen. Why is it there and what’s it reflecting. He said what you’ve said, that there’s an automatic CR associated with each of the three fitting levels at each frequency. He can click on any of the numbers in the chart beneath the fitting graph and see what the CR is for any of those points. But he can’t change them individually.

He did say that less automated processing might be better for my loss and my long-term experience wearing hearing aids, so I’m going to figure out some kinds of testing to do between the General and Music programs. If you’ve done any of that kind of testing yourself and have any suggestions I’d be happy to hear them.

1 Like

There will be a marked difference between General & Music, for sure.
Back to compression, the Music program will minimize it in order to allow the dynamics of the instruments/voices to be heard with less coloration, and processing.
It may be difficult for a normal listening environment, because all the emphasis on speech is removed, so this could be a problem, depending on your loss.
Best bet is A/B compare the 2 programs , and judge for yourself.

If you plan on staying w/ Philips 9030, accept the fact that CR’s are going to be automatically adjusted by software, based on the overall fitting values.

1 Like