T-coil

The name T-coil stands for Telephone-coil. Talking over the phone was its original purpose. Nowadays, T-coil is used on many other cases, not just for solving phone talking issues.

Using T-coil

When you switch to T-coil mode in your hearing aid, you choose to use a different ‘input’ to the hearing aid, the T-coil, instead of the microphone.


One of the biggest advantages of the T-coil is that it is generic and widely spread on many different hearing aids. It is not unique to a certain company. Given that a hearing aid has a T-coil option, you can use many other options as the source, not just the phone. For instance, a neck-loop, or hearing loops they use on public places. All of these instruments send magnetic signals that the T-coil can receive inside the hearing aid and translate it into audio sounds.

T-coil usages

These are the most common cases in which you can use your hearing aid in ‘T’ mode.
  1. Talking over the phone. Just by switching the hearing aid to ‘T’ mode and placing the handset next to your ear.
  2. Talking over the phone, while the phone is connected to some intermediate cable or device. See the illustrated example below.
  3. Public places. On some public places, they use hearing loops, which means they broadcast some audio to the air using special infrastructure. It sends magnetic signals and you can only hear it using a T-coil.
  4. Neck loops. Neck loops are a wearable component that goes around your neck. It is connected to some audio source like your TV. The neck loop transmits a magnetic signal that you can receive once you switch your hearing aid to ‘T’ mode.

Example

This is an example of one usage out of T-coil. It illustrates a cord that connects your phone, for instance, to your hearing aid. It is doing so by using a shilluete as the magnetic inductor placed next to your hearing aid.


t-coil hearing aidsthe Cord can be connected to a phone or to any music player (*). On the other side (**) a Silhouette inductor is placed next to the hearing aid. The T-coil receives the magnetic signals from the silhouette and transforms it to digital signals.


How T-coil works

The best way to explain what T-coil is, is to think of it as a microphone for electromagnetic signals. Any device that transmits these signals can connect to the T-coil inside your hearing aid.

Another way to think of it:

The microphone in your hearing aid reacts to sound waves and turns it into electric signals. T-coil, on the other hand, reacts to a magnetic field and turns it into an electric signal inside your hearing aid.

On T-coil’s original use, it gets the magnetic signal from a phone. It bypasses the phone’s speaker and the hearing aid’s microphone. Instead, the phone’s magnetic signal is transmitted to the T-coil.

This way, you can save lots of noises, and the overall hearing of the phone is improved.





Important note and a disclaimer

I write this for the sake of hearing aids users that find themselves confused by all the wireless terminology and misunderstandings. Therefore, I try to keep things as simple as possible and I simplify things to make them clearer. In addition, the discussion here is in the context of hearing aids and hearing aids’ users. I don’t try to cover the entire wireless world here, and therefore, all the data is observed from the angle of a hearing aid user and for his/her benefit.





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