Receiving Bluetooth on iPhone

My dad is currently in a nursing home that requires him to keep the volume on the tv low. He cannot hear well enough for the allowable volume. They gave him headphones to plug into the tv but he has a broken hip and can’t get up to plug and unplug them (the cord is in the way and his roommate keeps walking into it). He has a 6s iPhone and I have a Bluetooth transmitter I want to plug the transmitter into the aux on the tv and allow him to use headphones plugged into his phone. I have searched for an answer and have only found where people are saying iPhone can only send audio and not receive. This does not seam correct though because if you use Bluetooth for calls the phone has to receive your voice from your Bluetooth device to then transmit to the person your talking to. If someone knows how to set this up or knows of an app that will allow this some help would be greatly appreciated. Also I know this can be accomplished using a BT transmitter, amplifier, and a BT receiver but that would require the purchase of the amp and receiver, complicate the set up, and create more failure points with all the different power cords or needed batteries. Thanks.