There are three approaches to incorporating hearing loops in public spaces:

• As built-ins, which are designed uniquely for each space by specialist consultants and become part of the building's structure.
  These are most common in large passive hearing environments, like auditoriums, theaters, concert halls, and houses of worship.
  
• As fixtures, which are attached to the ceiling and create individual hearing loop environments directly underneath each unit.
  A hearing loop fixture is installed much like a lighting fixture and can be removed and reinstalled elsewhere as the needs of the space change.
  These are used primarily in museum exhibits and at public agency service desks.
  
• As appliances, which are mats or carpets placed on the floor that create individual hearing loop environments for people standing on or sitting above the floor piece.
  These require no installation and are designed principally for consultation environments.
  

As Emcom Systems has learned from more than a decade's experience designing and building critical communications systems, the best solution for deploying any communications technology puts human factors considerations at the forefront.
This means tailoring a system design that meets two objectives: addressing the listening experience in the environment at hand and realizing the desired outcome from each contact scenario.
It is important to recognize that the most successful listening experience may result from a combination of complementary auditory and visual aids - for instance, listening equipment combined with speechreading (previously called "lip reading") or text displays.
The best design is based on an analysis of each contact scenario to determine the effect of each aid.
For example, our hearing loop fixture product, Hearing Point, is an outgrowth of a project for New York City Transit.
The goal was to make our passenger assistance telephones more supportive of the hard of hearing.
These phones are housed in identifiable kiosks on subway platforms, an environment replete with background noise and without any supportive visual language cues.
Each kiosk contains a call button and a microphone/loudspeaker combination positioned at the average adult head level.
The desired outcome is allowing subway passengers to ask questions or report emergencies and to hear and understand responses, which could include critical instructions.
Because there's no visual component, this has to be accomplished entirely through auditory means.
The most effective way to serve hard of hearing passengers was by using a hearing loop.
With a hearing loop, the response signal is transmitted directly to the T-Coil in listening equipment many of these passengers are wearing already.
This effectively puts a clear response signal, without any background noise, right into their ear - true hearing.
The design arrived at involves sending the response signal both to the loudspeaker and to a hearing loop fixture, mounted within the kiosk, which maintains a hearing loop field roughly the size of one person - the passenger using the phone.
In addition to auditory clarity, the Hearing Point design has these advantages: the fixtures are easy to manufacture in quantity, are readily adaptable to different locations, and don't interfere with other hearing loops that might exist in the vicinity, like other passenger assistance telephones or token booths.
Many face-to-face consultation scenarios - especially those with expert professionals, like doctors, pharmacists, lawyers, and financial advisors - present their own set of subtle challenges.
In these contact scenarios, the professional needs to communicate a wealth of complex, detailed technical information efficiently to one or more clients.
Facilitating this is a challenge in itself, but is insufficient to realize the desired outcome.
To achieve success, hard of hearing clients have a role to play.
The solution must provide a supportive environment that encourages them to participate in the first place and helps them make the best use of their listening equipment.
On the surface, it would seem that since all participants in face-to-face consultations are visible to each other, speechreading could serve as an effective complement to their listening equipment.
This is not so clear-cut.
Linda Kessler, from the Shelley and Steven Einhorn Communication Center for Hearing and Communication in New York City, gave an excellent presentation on speechreading at the Hearing Loss Association of New Jersey annual meeting last November at the East Brunswick Public Library.
In it, she identified a number of language elements that make speechreading difficult.
These include long or uncommon words, proper nouns, and numbers - all of which are likely to occur in abundance in face-to-face professional consultations.
Also, in these scenarios, the topic is likely to be unfamiliar, the import of the discussion is liable to increase anxiety, and the conversation might be in the client's second language.
All of these factors tend to reduce the effectiveness of speechreading.
Since we cannot rely on an effective contribution from speechreading, the best solution is to provide the clearest possible auditory experience and inspire clients to take full advantage.