Today Denon announced [JP] they will start selling their first noise-cancelling headphones at the begining of August. The on-ear AH-NC732 will be available in black and silver.
The headphones come with a frequency response of 5Hz-28,000Hz, an impedance of 40Ω and a maximum power input of 100mW. Denon claims noise will be cut by 99%. One AAA battery is needed for 40 hours of active noise cancellation.
The headphones will cost $350 in Japan. Denon already offers a number of headphones in the USA, for example, so it would be no surprise to see the AH-NC732 find its way to markets outside Japan soon.