Induction loops and infrared systems replace the sound path between the sound source and the hard-of-hearing person with either an inductive (magnetic) or infrared signal that is not affected by acoustics or other sounds.
The hard-of-hearing person uses a receiver that converts the signal back to sound. With loop systems, this is usually their own hearing aid (only those with a ‘T’ position). Infrared systems use special receivers to convert the signal back to sound. Both systems enable users to hear from anywhere covered by the system. The sound that people hear without a receiver is unaffected.