I compared several ear protectors and this was the best one:
Best: Leightning L3 R-03318:
Howard Leight R-03318 Leightning L3 Shooter's Premium EarmuffNRR rating 30
Attenuation at various frequencies: 34 at 125, 36 at 500, 38 at 1000, 44 at 4000, 45 at 8000
Very comfortable, lightweight, fully adjustable without fear of breaking it, padded headband.
Muffles office chatter, typing, and lighting or computer humming very well. Does something, but not enough, to block loud mechanical hums and banging.
Bottom line: This is my new favorite. It's so comfortable!
Acceptable: AO Safety 90559
AO Safety 90559 Folding EarmuffNRR rating 21
Attenuation at various frequencies: Don't know
Comfortable, lightweight. Plastic unpadded headband adjusts in preset increments, and you have to be gentle when you put it on to avoid breaking it; the plastic broke after a couple years.
Reduces the volume of voices but doesn't block them, muffles lighting or computer humming, actually amplifies the sound of typing.
Bottom line: Despite its lower NRR rating, I used this one for years and liked it a lot.
Uncomfortable: Peltor Optime 105 H10A
Peltor H10A Optime 105 Over-the-Head EarmuffNRR rating 30
Attenuation at various frequencies: 21 at 125, 37 at 500, 41 at 1000, 43 at 4000, 41 at 8000
Uncomfortably tight fit, heavier than the others, padded adjustable headband.
Muffles office chatter, typing, and lighting or computer humming well. Does something, but not enough, to block loud mechanical hums and banging. (Same effectiveness as the Leightning)
Bottom line: This was effective but so uncomfortable squeezing my head I didn't want to wear it. And I have a small-ish head.
Unwearable: Tasco Golden Eagle 2950
Tasco 210-02950 29db Golden Eagle Blk 1pos Ovr-The-Head Earmuff(sold by another vendor as "built to military specifications", no brand name given, at twice the price)
NRR rating 29
Attenuation at various frequencies: 21 at 125, 36 at 500, 43 at 1000, 37 at 4000, 36 at 8000
Very uncomfortable. The adjustable headband looks padded, but in reality there's a piece of unpadded plastic that digs straight into the sides of your head.
Did not block sound for me at all, because the earpieces were too big for my head, leaving a gap. Maybe this would fit better on a man with a big head.
Bottom line: Hated it.