Wireless headphones, sometimes called cordless headphones, are small electronic speakers that a user can wear close to his or her ears to listen to sounds provided by a device but that are not connected to the device by wires. The sounds typically are transmitted from a device, such as a digital music player or smartphone, to the headphones using radio frequency waves. Some early versions transmitted the sounds using infrared signals. The headphones can be as large as padded cups that cover the ears or as small as earbuds that fit snugly into the ear canals. Wireless headphones can receive signals up to a certain distance away from the source device — usually at least 100 feet (30.5 m).
Uses and Advantages
These headphones are convenient for use during activities when wires would get in the user's way. For example, someone who is doing aerobic exercise or basic housecleaning might be able to move his or her arms more freely without worrying about getting tangled in the headphone wires. Wireless headphones are able to be secured somewhat to the user's head or ears, such as a strap the goes over the top of the head or hooks that curl over the tops of the ears, so the user does not have to worry about them falling off during normal activities.
Many people use wireless headphones with small devices that are somewhere on their bodies, such as clipped to their belts or held in their pockets or special holders that were designed for the devices. It can be convenient at times, however, for a device to be placed somewhere nearby instead. This can allow the user to move around more freely or perform activities that might damage the device. He or she also can move to other rooms, if necessary, as long as the headphones' range is not exceeded. Wireless headphones also can be used with large source devices, such as video game consoles or stereo systems, that cannot practically be moved with the user from place to place.
Disadvantages
Compared with wired headphones, there are a few disadvantages to using wireless versions. The main one is that they are not connected to a power supply, so they either need to be powered by batteries or need to be recharged on a regular basis. It could be inconvenient for the headphones to suddenly lose power and quit working while someone is using them.
Another, less-common disadvantage is that the headphones might lose the signal from the source device or experience interference. For example, if the user is in a different room from where the source device is, and if there is a significant barrier in between, the signal received by the headphones might be weakened. There also is a risk of other radio waves interfering with the signals that are being sent from the device to the headphones. Many wireless headphones have multiple channels that can be chosen to change the frequency of the waves being sent and received, which might help limit or eliminate this type of interference.
