Hearing devise
 

I got my devise from the v a. Plugs into tv and comes into my hearing aids where I can adjust the volume. Television sound is completely independent and can be adjusted and makes no difference to my hearing aid sound.

TV sound
 

I have a pair of Beats headphones when hooked up via Bluetooth, I can adjust the volume in the head phones and at the same time my wife can put the TV volume at whatever level she likes

I misread the OP. I thought they didn't want to hear the TV sound through the TV speakers. I could be wrong, but I think you can connect more than one speaker to the audio output. In that case, you could connect the hearing aids and another speaker, like a soundbar, to the audio output. Also, you would get better sound even with a cheap soundbar. I never use the internal TV speakers anyway.

Pinball wizard is correct. A splitter and soundbar should solve your problem. Cost of splitter about $5. And you could get a decent sound bar for less than $100

My hearing aid box (Starkey) has both an optical input and a 3.5mm jack input. I use the optical output from tv to soundbar, the I bought rca to 3.5mm cable for the hearing aid box.

use closed caption option for her

I have had two different boxes from hearing manufacturers. Both have had sound from the tv and to my hearing aid at the same time. Use the digital out put on the tv and the hearing aid box. If you don’t have a digital output it may be the tv.

box
 

I got a costco hearing aid and tv box at costco. I control my sound volume on the hearing aid and the tv sound is the remote at it's own level

write down the brand and model on it all and to to electronic store

Bought wireless ear insert headset
 

I bought Avantree HT4186 headset from Amazon. The transmitter connects to the TV and the headset inserts into ears like hearing aides. It's a totally separate audio volume control, on the ear set, so it doesn't affect the TV sound at all. It's easy to set up and works very well. The head set is wireless.

These still require the TV to have the capability to allow the use of these without disabling the internal speakers.
Not for TVs with non-functional audio out ports (test before purchase). When hooking up an external audio device, some TV internal speakers might not work or become muted. This is TV’s feature

Per Samsung "You can connect the TV to a Bluetooth speaker or headset, while using the TV speakers, by going to Settings>General>Accessibility>Multi-output Audio. This will allow using the TV speakers while connected to one Bluetooth device."

That doesn't work on my Samsung TV.

Not universally true, while it may be that way for your setup.

We have a Samsung TV, and I use Costco/Phonak hearing aids that use Bluetooth. I use a TV Connector box, also Bluetooth, that is connected to the TV's audio out jack via an optical (Toslink) cable. The TV Connector streams the audio directly to my hearing aids indepenent of the TV speakers. This allows me to hear the audio perfectly, while my wife can adjust the TV volume to her liking.

But then she would be hearing the sound directly in her ears AND the sound coming from the TV speakers. The TV speaker sound would sound muted, or unintelligible, or even screechy if her hearing aids are set certain ways.

I can wear my hearing aides, hear streaming from the streaming box through my computer, while also wearing my wired stereo headset plugged in to the back of my computer. I can hear the sound coming from both devices.

I'd never want to though, it's horrible, everything echoes.

On most TVs, if your speakers come from the TV itself and are not external speakers, you can't stream sound into your ears and output through the speakers at the same time. And for those TVs that let you do it, whoever is wearing the hearing aids will hear some kind of distortion, echo, screeching during commercials or music. That's because hearing aids are NOT noise-cancelling devices. They'll hear whatever sound is in the room (the TV coming through the speakers) PLUS whatever is being streamed into their ears (the TV coming through the streaming box).

I think that is only true if you use the bluetooth feature on the streaming box. But, you can buy an external bluetooth transmitter for about $20 on Amazon. It's a small 2-inch device that works great.