ATH-ANC27 QuietPoint active noise-cancelling over-ear Headphones offer an outstanding combination of performance, value, comfort and portability. The headphones provide up to 85% noise reduction, and deliver exceptional Sound quality with powerful bass, a natural midrange, detailed Treble and precise imaging in an immersive soundfield. A detachable cord enables their use as cordless noise-cancelling headphones; the Audio functions even if the Battery runs down.