In other words, why would anyone who invested (dearly) in hearing aids or cochlear implants needs anything more than their own devices? To be blunt, personal hearing devices don’t work the same way that eyeglasses do to correct a vision impairment. Hearing aids improve hearing and comprehension only within a range of about 6 feet.
Beyond 6 feet, people typically use a bluetooth system, in their home or office, to drive the audio signal from their TV or sound system directly to their hearing aid. That works in a range of up to 14 feet.
Beyond 14 feet, the distance from the primary source of audio to the hearing aid is so far that it gets blended in with ALL of the other background noises. That distance also causes some reverberation and distortion that is amplified by the amplifier built into the hearing aid. All of that leads to higher volume — but greatly reduced clarity and comprehension for the person wearing hearing aids.
The solution in larger, noisy spaces: shorten the distance that sound has to travel by generating an audio induction loop field that a telecoil receiver can pick up from anywhere in the looped space. All brands of hearing aids and implants are compatible with this system. Folks just need to be sure they know how to activate their telecoil. (82% of aids and 100% of implants have a built-in telecoil.)
For those who don’t yet have hearing aids, a “Loop Listener” a.k.a. “Telecoil Receiver” is extremely helpful. It will pick up the looped audio signal just as a telecoil-equipped hearing aid does.