The WH-1000XM4 over-ear headphones offer improved industry-leading noise cancellation (1), further improved sound quality, and even smarter features - now capable of adjusting not only to behaviour, but also location.Please note certain features of the WH-1000XM4 need to be enabled via the Sony Headphone Connect App before use.( 1) As of 21st April 2020. According to research by Sony Corporation, measured using JEITA-complaint guidelines. In headband style of wireless noise cancelling headphones' market.( 2) When using optional 1.5A or more AC adapter.