Advancements in hearing aid technology allow hard of hearing people to enjoy TV and listen to the radio just like those without a hearing problem. Moreover, new inventions make it possible for people with a hearing impairment to be more independent. An example is the possibility for a person with a hearing aid to use a telephone and to have a normal conversation without needing special equipment or additional help. Many telephones nowadays are equipped with features that make them compatible with hearing aids. Such telephones range from standard corded phones to modern smartphones, so a phone for every need and age can be found. In order to use your hearing aid with a hearing compatible telephone you have to make sure that your hearing aid has a "telecoil" (t-switch/t-coil) function. The "telecoil" function will let you change the standard microphone setting to a "T-setting" so that you can use your hearing device with a hearing aid compatible phone. How does the telecoil work? Standard hearing aids are equipped with a microphone and an amplifier to catch and deliver the sound to the wearer. The telecoil is used as a substitute or an addition to the microphone but instead of hearing sounds the regular way it "hears" magnetic signals that represent sounds. This function is usually not turned on by default so you have to turn it on when you want to use it. You can choose to use the telecoil only or to combine it with the microphone. Automatic telecoils are currently being developed and are still not widely available. The idea behind the telecoil was to process the magnetic signals emitted by the older telephones because their speakers used magnets to transmit sounds. Modern telephones do not use magnetic signals but those that are hearing aid compatible are equipped with special electronics to create such signals and thus connect to the telecoil function in the hearing aid and let you listen to the phone with clarity and without background noise. Which hearing aids have a telecoil? A telecoil is present in most hearing aids with the exception of very small ones, such as the in the canal hearing aids. When buying a hearing aid, make sure it has all the functions you need, including a T-setting. It is usually manipulated with a button or a small switch and may need manual adjustment to fit your exact hearing problem. It is recommended to consult your audiologist when programming the telecoil feature so it is suited to your individual hearing loss. Hearing aids with a telecoil can be used not only with telephones, though. With the t-coil and a neckloop you can listen to various audio devices such as an MP3 Player or computer. At hearingdirect.com you can find different models of hearing aids that are equipped with a telecoil. Both behind the ear hearing aids HD 300 and HD 400 Digital Hearing Aid have a T-setting and can be used with a hearing aid compatible telephone.