Something like AGC would be a big help.

I've done this with a floating window comparator. You AC couple the signal
to a peak detector, with a suitable discharge time, and then feed 2/3 Vpeak
and 1/3 Vpeak to a pair of comparators through RC time constants to
determine how fast the system should adapt to any given noise level.
Vpeak/2 is fed to the output comparators directly, or thorough a small RC,
to limit responses to impulses. This gives you an output when the signal
spikes above average, and another if it suddenly drops off.

But, that's a fair bit more circuits.

More than this, and I'd start thinking DSP :)

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