Potential signs and symptoms of a concussion include headache, dizziness, nausea, earringing, sensitivity to light and sounds, slurred speech, impaired memory or judgment, as well as changes in reaction time or balance.
What was interesting was that even though I could still hear most office sounds (like the phone ringing) through the ear defenders, the very act of wearing them gave off a subtle 'go-away-I'm-working' vibe that allowed others to ignore and exclude me without being impolite ... it worked for me!