Rolling your eyes to turn up the volume of a portable music player and tapping your fingers to turn on a DVD player are among technologies Japan's top mobile carrier is testing for "wearable" gadgets.

In one version, sensors and chips inside headphones detect electrical current produced by movements of the wearer's eyeballs, says Masaaki Fukumoto, executive research engineer at NTT DoCoMo.

"We are working on a cell phone of the future," he said at a suburban Tokyo research center.

NTT DoCoMo believes wearable control technology will be adapted for mobile devices that download music, play video games and allow users to shop online and keep up with their e-mail.

In a demonstration Tuesday for The Associated Press, researcher Hiroyuki Manabe wore a giant headset covered with wires to show how computer graphic lines in a monitor connected to the headset darted wildly whenever his eyes moved.

He turned up the volume on a digital music player by rolling his eyes, and he jerked his eyes twice to the right to fast forward.

The new technology may also enable cell phone cameras to read bar codes used in Japan to get product information, download music and coupons when the user simply looks at the codes, researchers said.

Fukumoto showed a wearable cell phone shaped like a ring about the size of a ping pong ball. When a wearer sticks his fingers in his ears, the sound travels as vibrations through his bones and into his ears, where it is heard as sound again.

Another iteration of the technology appears in a wristwatch that can detect the wearer's thumb and forefinger tapping together to work as a remote controller for such gadgets as a DVD player.

The days when wearable technology looks like fancy cumbersome space-suits are over. The latest look is everyday and inconspicuous, blending into the routine, Fukumoto said.

"Japanese don't like to stand out," he said.

But when such technology will become real products, if ever, is still unknown, he said.