Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Surprisingly Effective NR; not bad headphones, either

The noise reduction works as advertized. Low frequency sounds are _greatly_ reduced. Higher frequencies -- human voices, in particular -- are less damped. But if you spend time around machines (airplanes, air conditioners, etc.) they make your life a lot more peaceful. As headphones (for example, for a stereo) they are OK but not great.