I can say I haven't had this happen to me in a long time - I thought perhaps they had figured out what caused it.

I think I may have hearing damage from this (I wear a headset) - so I feel your pain.

To be honest not for a while, if I really concentrate I can still hear it

It only happened about 7 or 8 times but  each time I feared for my TV speakers

I have the Turtle Beach PX21 & PX5 and used to have this issue a lot (several times a day) on both headsets with MW3.  I resolved the issue by ensuring that none of the in game audio settings (i.e. music, voice and sound effects) are maxed out.  It has been a while, but I believe that I lowered my voice and music settings to almost the lowest settings and have the sound effects about mid level.   I made these changes shortly after the release of MW3.  Since this I have only experienced this Audio EMP twice. 

NOTE: I normally play with everything coming from the headset.  I always mute the sound system to prevent feedback. 

I am still getting the occasional one. I think I had one last week. Atleast it isn't as bad as it was in January through March when it was happening on a daily basis.