One night, at a performance of Wicked, Einhorn was stunned by the quality of sound he was able to hear from the performance. The sound was wirelessly transmitted to his hearing aid. The device is called a hearing loop; places install a copper wire around the periphery of the room which sends electromagnetic signals to hearing aids and cochlear implants. The sounds sent to the hearing aids come only from the microphone not the background. Because hearing loops are so effective, many are even installing them in their own homes. The hearing loop allows individuals with hearing loss to enjoy going out more to movies and museums which they once avoided because of the numerous background noises. Hearing loops also help those with hearing loss to avoid any embarrassment from using special headsets. Although the installation of loops in many places is more expensive than regular hearing aid services, many see it as a greater long term benefit.
If you click on the link to the article, under the first paragraph is the title Multimedia, click on the play button under Comparing Subway Sounds to hear the difference between hearing without a loop and with a loop.