These in-ear headphones have active noise cancelling to cut out ambient chatter
Good Gear Guide.au
1 December 2012
Summary: Polk Audio's foray into the not-so-popular world of noise cancelling in-ear headphones is a solid one: the UltraFocus 6000 headphones have good sound and competent active noise cancelling to complement the passive in-ear isolation. Our main issue is with the bulk of the noise cancelling's in-line battery pack and volume control. The sensation of noise cancelling with in-ear headphones is also a strange one -- moreso than with over-the-ear headphones.
Pros: Excellent passive and active noise cancelling, Good sound, pleasant bass and treble response