Nothing, personally.
And I continue to recommend audiology as the new, growing job field.
I figure after 30 years' worth of non-stop noise, that beat-down of hearing faculities, will result in a huge cash crop for the treatment folks.. Do ya think I-Pods blaring tunes stuck into the earholes morning till night, or 400 watt+ car stereos, home theaters with folks rocking on these floor-level chairs looking like a victim of a sad mental illness, grooving to 6 or so, screaming speakers...won't have an effect?