Best place to use the earbuds totally depends on how good the noise cancelation in your earbuds is. All the noise canceling earbuds perform well in less noisy places like the library, and office. The real test starts in situations like heavy traffic. And the toughest one happens to be in Airplane. Not all earbuds perform well in Airplane. Traffic noises, on the other hand, could be canceled out with any decent noise canceling earbuds. So coming back to the question. The best place to use earbuds is directly proportional to the quality of noise cancellation in it.