Trying to learn about hearing aids and "gain"

Pick your loss at one frequency. Look at the G65 (amount of gain for 65dB input) then work it out like this:

Loss of 40dB (S/N); Gain circa 13dB + input 65dB = output 78dB
Loss of 40dB (cond.) Gain circa 20dB + input 65dB = output 85dB

Loss of 60dB (S/N) Gain circa 20dB + input 65dB = output 85dB
Loss of 60dB (Cond.) Gain circa 30dB + input 65dB = output 95dB

Loss of 80dB (S/N) Gain circa 27dB + input 65dB = output 92dB
Loss of 80dB (Cond.) Gain circa 40dB + input 65dB = output 105dB

Mixed losses will combine proportionate elements of both. Extrapolate away for figures either side or different input levels.
Actual manufacturers will bend these rules to fit their Hearing Aid strategies and particular algorithms, according to whichever fitting philosophy or AI dynamics they incorporate.
So you’re unlikely to get an exact implementation of the above whichever way.

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So does this mean for my 60db loss at 1000hz my hearing aids are powering out 80db for me to hear this? I’m trying to work this out too🤦‍♀️ So are hearing aids trying to make what you can’t hear louder into the part of the audiogram you can hear?

For a 65db input? maybe. It really depends on what was recommended by the fitting formula and how it has been adjusted by the HCP. The 80db output would not be for all volumes at that freq. Quieter sounds get more gain and louder sounds get less, but the range of sounds along the volume curve should sound naturally louder as the inputs get louder.

WH

A couple of math errors I think. Just mentioning as I suspect many people find this pretty confusing without having numbers that don’t add up.

Loss of 60dB (S/N) Gain circa 20dB + input 65dB = output 80dB (20+65 should be 85dB)

Loss of 80dB (Cond.) Gain circa 40dB + input 65dB = output 125dB 40+65 should be 105dB)

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Fixed. Cheers, it’s after wine time here :wink:

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More like 85 dB for a speech 65dB input.
So:
1/3 gain of a 60dB SN loss = 20dB + 45dB input = 65dB

1/3 gain of a 60dB SN loss = 20dB + 65dB input = 85dB

1/3 gain of a 60dB SN loss = 20dB + 85dB input = 105dB

1/3 gain of a 60dB SN loss = 20dB + 100dB input = 120 dB - but you’ll probably be hitting your MPO limiters there.