As I found while researching this article, the statutory requirements relating to Hearing Augmentation Systems (sometimes referred to as Hearing Assistance Systems, or Listening Systems) in NZ buildings are Convoluted, Confusing and Contradictory. But I knew that – that was why I thought it would be a good topic for this column; I still wasn’t prepared for how much CC&C there actually is!
And to make it worse, compliance is signed off at the individual Territorial Authority level, and the interpretation of what is deemed to comply varies from Authority to Authority; sometimes from Building Surveyor to Building Surveyor.
Hearing Augmentation Systems are systems put in place to allow aural information to be conveyed to Building Users clearly and accurately. The Building Act and NZS4121 (Design for access and mobility – Buildings and associated facilities) are clear that the scope includes users who don’t require hearing aids; however, the Building Code clearly states the requirement is only for persons requiring hearing aids (G5.3.5). The guidance that is given in these documents and other related materials is that the Building Code is the minimum standard and the expectation is that an adequate solution will be designed for a given space, taking into consideration the requirements of the particular location and function of the space. There is also a requirement that Hearing Augmentation systems are maintained 6-monthly. In theory, they should appear on a building’s compliance schedule and are part of the Building WOF process. Also, because they are disability systems, the building must have prescribed signage.
Hearing Augmentation technology and Hearing Aid technology are both in the middle of the technological revolution – both are adopting “new” digital techniques and methods to implement the required functionality and feature set. Hearing Aids, in particular, are adopting new technologies rapidly such as linking to a user’s smartphone. The drive for miniaturisation, however, means that Hearing Aid manufacturers are increasingly leaving out the T-coil which has been the basis for Building Hearing Augmentation systems since the 1960s. The next 10-years will be interesting as the new technologies are trialled and adopted, and transition through the hearing aid population. Hopefully, it won’t take the legislation too long to catch up.
Hearing Augmentation Systems
So, what types of Hearing Augmentation systems are there?
Sound Capture
Firstly, all Hearing Augmentation systems require a system of microphones or other audio input. This can be built into the system itself or can be acquired via a sound system. In some circumstances, this means the sound system needs to be left on even though it is not needed in its own right.
Audio-Frequency Induction Loop Systems (Hearing Loops)
These loops are usually installed in meeting rooms or in other places where people gather. They assist people who have hearing aids fitted with a T-switch. They can also assist people without hearing aids if the user is provided with a loop receiver device.
In addition to permanently installed hearing loops, there are portable hearing loops available. These can be used in small spaces such as meeting rooms or motor vehicles. Loops are sensitive to building construction and other wireless frequency emitters (including other Hearing Loops, so they are not good in multi-room environments).
Infrared Systems
Infrared systems take the sound input signal and broadcast it on an Infrared frequency within the space, which is then picked up with a system-specific receiver worn by the user. These systems generally require a direct, unblocked, line-of-sight to the user and require users to obtain and wear a receiver with the appropriate attachment. They can be used by users without hearing aids. They are sensitive to very bright lights and sunlight and the receiver unit must be worn outside clothing etc.
Building operators need to keep a supply of receivers, batteries and headphones forbuilding users to use as required. Headphones or in-ear devices are subject to Public Health cleaning requirements.
FM Wireless Systems
Structurally, these are very similar to Infrared systems but use FM radio frequencies rather than Infrared frequencies. Consequently, they are not limited to direct line-of-sight. Receivers can consequently be put in a pocket or handbag with relatively minor impact to performance. While they are not impacted by sunlight, they can be affected by other wireless emitters.
There may be some old wireless systems around that use VHF radio frequencies. Given the recent changes in frequency allocation in favour of mobile phone service providers, continued use of this band is problematic.
Peter Lane is Principal Consultant at System Design & Communication Services and has over 30-years’ experience with Technology systems. We invite your questions, suggestions and ideas for articles. These can be submitted either through the editor or by email to dct@dct.org.nz. We also operate a website focused on building a community of people who are interested in improving the way we can use technology located at www.dct.org.nz.
