To use a telecoil in a place that has installed a hearing loop, all you have to do is turn the aid to the telecoil mode and you'll connect with the system in the room. Telecoils have to be activated in hearing aids by your audiologist/provider. Often they don't bother to turn them on. You don't need any external equipment in a looped room/venue.

To use telecoils with FM or IR (Infrared) systems you will need a neckloop, which is a small circular wire that plugs into a receiver that the venue is expected to provide. That puts you in 'the loop' and again, it's a matter or turning on your activated telecoil. In newer hearing aids that will likely be done with your smart phone. In older models it's by pushing a button on the hearing aid.

I use the neckloop with several different audio devices, including my cell phone, laptop, portable radio, etc. It's rather like having binoculars for your ears as it brings sound direct to you without any background noise,

You can see where loops are installed at http://www.hearingloop.org You should know that venues are required by the Americans with Disabilities Act to provide communication access in public venues where listening is needed to participate. The downside is that they don't have to provide that access unless people ask for it. YOU have to advocate and educate.

Are you willing to do that?

Further clarification. Movie theaters are not exempt from providing communication access, but most do it with captioning devices. They are helpful, but a lot of people say they dislike them. Rarely are movies open captioned in theaters, except in regions where people with hearing loss have advocated to have open captioning. In most cases, that is done for one or two of the timelines for a particular movie...most often a matinee.

Ask at your local theater about captioning devices. The most common one is Captiview. It's a device that fits in the cup holder at a theater seat. It's a flexible hose that leads to a small captioning screen that can be adjusted to a level where it works for you. It works, but people complain that it doesn't provide captions for the previews before the movie begins. Therefore, you can't test it until the actual movie begins.

I definitely use this device when/if I attend movies. Like so many other people with hearing loss, I prefer streaming movies at home on the TV with captions and volume I can control.

Hearing loss has been part of my reality since long before these caption devices and streaming was available. For years I just didn't 'do' movies. I read books instead. It's been fun getting back into knowing what people are talking about in movie conversations. 🙂