I'll take r-squared loss for 40 dB, Alex :)

Given Keith Moon's love for explosives I wouldn't be surprised if their pyrotechnic stunts helped this along too, like the accidental overdose of gunpowder in the bass drum on The Smothers Brothers Comedy Hour.

One of those drum explosion incidents was credited with the deafness in one of his ears. (IIRC, been a few years since I saw the documentary)