Although these aren't noise-reducing, they do a good job of shutting out ambient noise

Except...even though the B&O's are not noise-canceling they do a great job of muting outside noise.

Sound deadening -- 4 -- they do a good job of isolating noise

They did a great job of blocking all of the sound associated with plane engine noise or babies crying

The B&O's are comfortable and can be worn for extended periods, like I did this afternoon

In terms of sound quality, these B&O are awesome.

The B&O did well with amplified upright bass too: a warm, growly sound that's enjoyable to listen to