Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Good headphones, noise canceling not so much

While I agree with previous reviews that these are comfortable headphones, I have had problems with the noise cancellation aspect of them. I bought them with the intention of blocking out the hum (both man-made like conversations in a library or mechanical like airplane) and they are only satisfactory. Often they will actually cut out the noise of whatever podcast I am listening to, which seems to defeat the purpose. Overall I wish I had spent a little bit more and gotten a pair of headphones that would do the job better.