Koss QZ900 Noise Cancelling Headphoness

Once this incoming noise can be analyzed, the Koss QZ900 circuit introduces a sound wave that is 180 degrees out of phase with the incoming signal. The result is what Koss engineers term “zero earth” at the point of the eardrum. Most low-frequency distractions from airplanes, lawnmowers, fans or even office hum will be dramatically reduced by these noise-cancelling headphones.

Koss QZ900 noise-cancelling headphones will create less reason to turn up the volume and overdrive the tiny amplifier in your portable electronics. This means greater efficiency, less distortion, deep rich lows, and sparkling highs.

Unlike most other noise-cancelling headphones, QZ900s play music with or without the active noise cancelling circuit engaged. A handy removable cord features in-line volume control, and one standard AAA battery provides approximately 50 hours of active noise cancellation.

• Active Noise Reduction
• Cord unplugs for wire-free passive and active noise?cancellation
• Folds flat for portability
• Carrying case included
• In-line volume control
• Koss?Limited Lifetime Warranty

Key Features:

• Revolutionary Active Noise Reduction (ANR) headphone system reduces harmful and annoying low frequency sounds in noisy environments
• Closed leatherette ear cushion for added passive noise reduction
• Cord unplugs to enjoy passive and active noise?cancellation?wirelessly
• Straight single-entry 4-foot cord with in-line volume control
• Fold-flat for portability; carrying case included
• Covered under the?Koss?Stereophones?Limited Lifetime Warranty