Can anyone help me understand what is the difference between Gain and MPO ?
What difference does it make to hearing, if i just increase MPO without increasing the Gain or Vice-Versa?
I am bit confused between both.
I am bit confused between both.
Hello,
Gain is extra dB added. MPO is a limiter to these gains.
MPO = Maximal Power Output
G80 = Gain for 80dB band
G65 = Gain for 65dB band, etc.
Example
So if a sound is picked up by the microphone, it gets digitized into frequency parts and those parts get amplified. So a simple tone of 6kHz digitized as 65dB loud, would gets a boost of 28dB, resulting in an generated sound of 83dB. However a sound of 6kHz of 90dB would get a boost of 25dB, resulting in a sound of 115dB. This is louder than the MPO at 6kHz, so it gets capped at 112dB.
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Thanks Mark for providing Clarity. So you mean, if I increase MPO at 6k from 112 to 115… this will result in boost of 25db of 6k at 90db as well
in otherwords, Just increase MPO in HA will not have any effect unless Gains are increased upto that level maximizing ouptut.
Please correct me, if my understanding is wrong
Correct.
No, it will have an impact. Very loud sounds will be amplified up to that limit. Just imagine a 100dB sound at 125dB! That’s a jack hammer made into a pneumatic hammer.
I understand from your audiogram that you would love to hear more in the upper frequencies: Be careful, though, you don’t seem to have much hearing left there! The MPO values are limiting values. If you keep upping them, you could damage your ears. Remember that it doesn’t have to be painful for very loud sounds to damage your ears: Prolonged exposure will work, too. So ask around, preferably your ENT to see what are healthy limits.
Try to do a UCL in situ measurement. UCL stands for Upper Comfortable Levels/Limits. You’ll notice that you rather have the MPO at values where they actually form a limit, increasing them will effectively disable this feature.
Reasons to play around with your MPO values are usually for comfort. The kicking in of the limit can produce sound artifacts: distortions, clippings, etc. So when I wanted to check whether the MPO’s had an impact on playing the piano, I upped them. Aside from experiments, I have always found that I rather have lower values for MPO. I can understand almost all speech at 85dB, so there is really no win in amplifying the hell out of everything. And with two little girls running around the house, I tend to be less annoyed if my aids don’t amplify beyond what is reasonable. 
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Thank you Markismus 
Just reporting in as my curiosity was piqued by the discussion of MPO vs gain, the UCL measurement and related topics. I was at my audi today to tweak the MPO/gain proximity a TEENSE. I am hoping for that tiny, noticeable extra boost in clarity at the high end to help speech in LOUD noise. Not sure if I did the right thing, but I think my Phonak Lumity Life settings shows: ain’t much space to maneuver under that MPO boundary!
I can’t do a thing at the lower frequencies, but my audi did step up the higher freqs a couple notches - almost immediately, I noticed a sort of muddied/muffled outcome tho! That surprised both of us, so she took it back down a step - slightly above the original setting I walked in with.
I’ll keep these as shown below on ONE pair of Lumity Life aids.
If my world sounds a bit better, I’ll have her make the same change on my backup pair. So far, I don’t really notice ANY difference in sound, but that’s preferable to the slight muddied outcome she tried.
I guess I’ll never give up that quest for perfect speech comprehension in LOUD noise! I mentioned that my Roger V2 stick sometimes picks up TOO much ambient sound when I’m in a noisy place, but I think I have two options here: 1.) turn the volume DOWN on my aids, or 2.) put aids into Speech in Loud Noise and jack the volume UP a bit. That dedicated program is set to as narrow a beam as possible, so I think this is as good as it gets for now!
Thanks for that observation! Yes, I noticed how the line of MPO seems to give me a decent margin till I hit the ceiling of these Lumity Life aids. In fact, you just jogged a memory of mine: the initial setup was so awful that we ended up copy/pasting the setup I had on my Marvel aids and so that’s what my current setting is on both pairs of Lumity Life aids. Maybe that’s why the MPO is in its current position?
Ack. Would I be a BUG if I asked my audi to just bump up the MPO? Is that a setting independent of gain that can be set HIGHER? I seem to recall in older aids that my MPO would be touching that ceiling or even stepping a bit INTO the greyed-out area shown.
Well, I need to get back in to see my audi cuz I only had this tiny change made on ONE pair. It doesn’t really sound any different than before (probably a good thing!).
Does anyone here know if MPO is PRE-SET by the manufacturer? Or is it determined by the usual hearing tests given before the aids are programmed? I know I didn’t have that tinkered with yesterday. Perhaps needs looking in to…
I’ve never known an Aid to have gain and MPO so close in my life with Phonak Target especially when MPO is no where near max.
I have no idea why yours is that way. They are both literally touching.
I wonder if Audi lowered them slightly.
If you want the MPO raised, raise it by 1dB each time so not too quickly.
Yes, in fact, isn’t that why I’d get distortion at the lower frequencies if the volume is too high?
We didn’t make changes to Noise Management, but it seems that my aids are still too aggressive in loud places. iI’s like someone has put a pillow on top of them. They get MUFFLED really low for several seconds as if some algorithm is just putting a LID on everything. This happens when streaming movies or even being out in a super noisy place.
Thoughts?
So it sounds like my audi could boost that MPO UP in the Target software - it’s a line that can be adjusted (like gain)? Wonder why we didn’t explore that option yesterday?
Yes in the picture it’s highlighted and you can raise or even lower if.
Can’t say for sure but I think so.
Thanks for the info!
Ack. I feel dumb as a donkey for not knowing this beforehand. I don’t mean to pester my audi, but dangit, I’m going to go back in to ask about moving that MPO. I could shoot my prevous audi an email … but that would probably not be cool, as I live cross-country from him now. 
OK. Here’s a way too dense article that indicates: " A low MPO suggests that the hearing aid saturates with distortion and/or goes into compression limitation at a low output level; a high MPO indicates that high output can occur without distortion/saturation."
So it sure sounds like I coulda, shoulda RAISED that MPO. I guess I’ll share this article with my audi?
And another interesting article on MPO levels and how that setting impacts speech comprehension in LOUD places. I think I’m on to something here. I would like to have my MPO boosted to give me better dynamic range for music and speech comprehension. I could even try turning the gain DOWN where it touches the MPO in the lower freqs.
QUESTION: Are these changes only possible using Target software? I don’t have that loaded, and am completely ignorant as to how to use it. Just curious if DIYers tinker with these MPO and gain numbers?
Yes you’ll need target and Noahlink to DIY.
No never, I’ve never needed to do this ever, those settings you have would not have been set by target, you audiologist has made some changes at some point, Evey single HAs I’ve programmed has never been quite that close to MPO.
Yes, I’m thinking it’s when I asked her to just “copy & paste” the settings I had for my Marvels into the settings for my Lumity Life aids. It really got me like 95% to perfection. Then I added a dedicated “Music” program and feel I am very close to conquering Everest! 
But having read about MPO vs gain I can’t stop my quest for the Holy Grail - hearing even BETTER in noisy places. I can see where the MPO at lower freqs should perhaps be separated out a bit, but I can also see where MPO can be raised across the board, enabling me to increase gain a tad throughout - perhaps esp at higher freqs?
If my audi was my sister, I’d sit her down right now and make her tinker and tweak with my aids in Target. But she has other patients and things on her platter. Even so, I can’t stop myself from the obsessive pursuit of perfection.