The ATH-WS990BT wireless over-ear headphones combine exclusive 53 mm Deep Motion Drivers with large, high-flux magnetic circuitry and Bluetooth technology to deliver vibrant full-range wireless audio with invigorating bass. The powerful magnetic force of the circuitry results in dynamic, well-tailored diaphragm response to reproduce deep, clear low frequencies and detailed mid-to-high frequencies. The sound is further enhanced by the exclusive dual-layer, memory-foam earpads, comprised of a firm internal layer and a soft outer layer, that provide excellent sound isolation and comfort. The headphones can even reproduce Hi-Res Audio when used with the included 1.2 m (3. 9') audio cable. In addition to providing high-fidelity wireless audio, the ATH-WS990BT headphones also feature noise-cancelling and hear-through functionality that gives you greater control over your interaction with the outside world and its noise. The headphones' selectable active noise-cancellation function dampens the ambient noise for greater enjoyment of the Solid Bass audio in loud environments. Conversely, the selectable hear-through function allows voices in the surrounding area to be heard through the headphones. This lets you listen for important announcements, say in a train station or airport, and hear the voice of anyone who might engage you in conversation. A mic and controls are built into the left earcup, giving you convenient control of calls and music playback on a wirelessly connected device. An audio cable is also included to let you use the headphones in areas where wireless operation is prohibited (e.g., in airplanes or hospitals), when battery power is low, or when you want to listen to Hi-Res Audio. The headphones' internal lithium polymer battery provides up to 30 hours of continuous wireless use (up to 1,000 hours in standby mode) and can be recharged using the included 30 cm (1.0') USB charging cable. About High-Resolution Audio In Brief: The Move to Hi-Res Audio While many listeners may believe that high-resolution audio came along with the introduction of the Compact Disc in 1982, constraints on the disc's storage space always prevented CD audio (standardized at 44.1 kHz/16-bit) from fully and completely reproducing the original recorded sound. The advent and subsequent popularity of MP3s only made this problem more pronounced - the necessary compression of these files causes audio information to be lost, thus greatly reducing the audio quality. But with lossless audio file formats, faster Internet speeds, and storage space increasingly easy to come by (and in ever-smaller packages), the push is on to create audio equipment capable of capturing and reproducing true Hi-Res Audio, generally considered to be 96 kHz/24-bit or better. The Hi-Res Audio logo certifies that a product meets the Hi-Res Audio standards. Per these standards, headphones must have transducer frequency performance to at least 40 kHz. As a producer of these types of audiophile headphones since 1972, Audio-Technica is well-positioned to provide audio solutions that meet the demands of Hi-Res Audio media formats, allowing for the full reproduction of their extended sonic characteristics.