They're not bad, but are relatively poor against sounds similar to human speech, which includes coughing, sniffing, throat clearing etc. My colleagues who have a large extractor fan just outside their window have reported that noise-cancelling headphones offer an improvement, though.

> noise cancelling headphones

They are very ineffective against voices! Passive insulating headphones are much better.

One problem is they don't cancel out the terrible odors you have to breath when you're packed in next to people who don't bath and eat at their desks.

I think the awful smells I can't escape are worse than the noise at this point.