Wireless headphones use several different technologies. Many operate on a radio frequency (RF) channel. Although that means you can wander around your house with your headphones, you can also get interference and static from other electronics that use radio signals, such as cordless phones and wireless routers. However, careful tuning can correct this issue. More expensive wireless headphones of this type have auto-scanning that will attempt to find a clear channel for interference-free transmission. At the higher end, some wireless headphones can maintain an acceptable signal from as far as 100 meters (nearly 330 feet) away.
Some wireless headphones use infrared (IR) technology. These headphones are less vulnerable to interference than radio frequency (RF) headphones, but you have to remain within sight of the infrared transmitter. Even then, there is the slight chance of interference by strong direct light from sunlight or glare from plasma screens. Infrared wireless headphones are most suitable for listening while stationary.
Bluetooth stereo headphones have gained in popularity in recent years, as more devices have become compatible with the latest A2DP standard, as well as the AVRCP standard, which allows users to navigate playback controls wirelessly. Bluetooth headphones are compatible with Bluetooth-enabled devices or with any device if the headphones come with a Bluetooth adapter. Other technology wireless headphones typically come with include a base unit that hooks up to your audio equipment and communicates with the headphones. The base unit also doubles as holder for the headphones when you're not using them, and some even act as a charging station.
Kleer wireless is a technology that receives lossless, CD-quality audio (unlike Bluetooth headsets where the audio is compressed) without interference (unlike many RF headsets). It also uses less power than Bluetooth, resulting in longer battery life, and it has a much larger range. So far, Kleer is only commonly available in sets from Sennheiser in the U.S., though TDK has also begun releasing headphones with Kleer technology.
Here's what experts say to look for in wireless headphones: