Loud environment protection

I experience tinnitus from not hearing frequencies for the letter S.

I am successfully using a HA which has halted my growing tinnitus.

When in a 85db+ environment for 3-4 hours, I wear earplugs to attenuate the sound level. However these do not boost the frequencies I am struggling to hear. The net result is my tinnitus appears to grow louder, possibly after my brain has been stretching to hear the S frequencies.

I'm looking for a supplier of inside ear sound attenuators, that I can have a tube from a spare HA which will provide my missing frequencies at a measured level?

Any suggestions?

Phonak Sky M70-M