@ChrisNZ - Thanks for the professional insight. Can you provide some examples of custom electronic plugs and what to look for in those? I double up with foam plugs and ear muffs, but I’m still looking for better protection.
I can't offer much insight into currently available electronic plug options as I'm in NZ and virtually all models available in the US won't be relevant here. My two pairs (near clones) are now over ? 8yrs old so have no bearing on current US amps. Mine were top-of-the-line (global brand) digital aids modified and converted to a shooting application. This included additional measures to improve the passive seal and shifting the mic off the faceplate up to the "helix" (cymba concha) to really reduce wind turbulence. Makes a huge difference.
The biggest issue is ( for want of the actual term) the response time for high-intensity impulses. You need to be well under 5 milliseconds, preferably 2, to fully capture rifle reports. Many chips in hearing aids have a much slower-acting AVC compression and the peak has already got through before the circuit controls them. Too late.
I guess you can ask what the response time of the circuit is to impulses but I doubt many suppliers will be able to give a valid answer. As I implied before, if the report sounds unpleasantly loud, chances are it hasn't be adequately captured by the circuitry.