The High-fidelity stereo sound benefits from the 40mm neodymium driver, CSR chip, and the around-ear cushion design which provide a well-closed and immersed enviroment for your ears, Just lose yourself in the music! NOTE: Mpow 059 headphones is passive noise isolating, NOT active noise cancellation(ANC), it can't cancel the noise completely but it won't drain the battery and damage the sound. 2. The closed-back design provides immersive Hi-Fi sound with CSR chip and 40mm driver together, it is better than ANC in term of sounds quality.