What is a Hearing Augmentation System?
A Hearing Augmentation system is installed to assist those that have a hearing impediment. A Hearing Augmentation system takes a sound source such as a microphone or video player and transmits a signal to to a user. The signal is then amplified via local headphones or T-coil enabled hearing aid or cochlear implant.
There are several Hearing Augmentation systems available these include hearing loops, Infrared systems and Radio systems.
A hearing loop, also known as an Induction or Audio Loop, provides a magnetic, wireless signal that is picked up by the hearing aid when it is set to ‘T’ (Telecoil) setting.
The loop system consists of a microphone to pick up the spoken word; an amplifier which processes the signal which is then sent through the final piece; the induction loop, a wire placed around the perimeter of a room or sanctuary to act as an antenna that radiates the magnetic signal to the hearing aid.
When a hearing aid user selects the ‘T’ setting; he or she can pick up the sounds spoken into the PA system’s microphone instead of the hearing aid’s internal microphone. This results in improved speech understanding because the listener receives a clear signal without any background noise.
An Infrared System uses Infrared Light to transmit audio to a receiver a description on how this works is outlined below.
1) Input to an infrared system can come from a microphone,sound system or another audio source. Here, the presenter speaks to participants using an existing microphone.This audio input produces an electrical signal which contains the audio information.
2) This electrical signal is then fed to the infrared modulator, which prepares the signal for infrared transmission. The processed signal is then fed to the emitter, which produces the invisible infrared light and radiates it into the room.
3) Infrared receivers convert the infrared light back to audio. Participants requiring hearing assistance each use an infrared receiver to listen to the presenter.
Where is a Hearing Augmentation System Required?
(a) A hearing augmentation system must be provided where an inbuilt amplification system, other than one used only for emergency warning, is installed—
(i) in a room in a Class 9b building; or
(ii) in an auditorium, conference room, meeting room or room for judicatory purposes; or
(iii) at any ticket office, teller’s booth, reception area or the like, where the public is screened from the service provider.
(b) If a hearing augmentation system required by (a) is—
(i) an induction loop, it must be provided to not less than 80% of the floor area of the room or space served by the inbuilt amplification system; or
(ii) a system requiring the use of receivers or the like, it must be available to not less than 95% of the floor area of the room or space served by the inbuilt amplification system, and the number of receivers provided must not be less than—
(A) if the room or space accommodates up to 500 persons, 1 receiver for every 25 persons or part thereof, or 2 receivers, whichever is the greater; and
(B) if the room or space accommodates more than 500 persons but not more than 1000 persons, 20 receivers plus 1 receiver for every 33 persons or part thereof in excess of 500 persons; and
(C) if the room or space accommodates more than 1000 persons but not more than 2000 persons, 35 receivers plus 1 receiver for every 50 persons or part thereof in excess of 1000 persons; and
(D) if the room or space accommodates more than 2000 persons, 55 receivers plus 1 receiver for every 100 persons or part thereof in excess of 2000 persons.
(c) The number of persons accommodated in the room or space served by an inbuilt amplification system must be calculated according to D1.13.
(d) Any screen or scoreboard associated with a Class 9b building and capable of displaying public announcements must be capable of supplementing any public address system, other than a public address system used for emergency warning purposes only.