Forum Proceedings

The following data was collected during the stakeholder forum and summarizes the comments of forum participants.

1. Needs (unmet customer needs)

• Need simple control to turn T-coil on/off - nothing more than T-switch


• Need T-coil receivers in smaller (ITE, ITC, CIC) hearing aids.


• Need T-coil receivers in hearing aids for persons with mild to moderate hearing loss.


• Need "walkman style" IR or FM receiver that interfaces to the hearing aid with silhouette, neck loop or DAI.


• Need receivers (of all types - IL, IR, FM) to be small and lightweight.


• Need receivers (of all types - IL, IR, FM) to be comfortable when the user is physically active (e.g. dancing, aerobics, etc.)


• Need IL systems (portable and permanent) that are easy for non-technical people to use (setup, install, and operate).


• Need simple instructions for setup, installation and operation (e.g. many people don't read or understand instructions) for IL systems.
• Need good sound quality (from hearing aid) from anywhere within the looped area.
• Need to install inductive loop systems properly.
• Need to follow standards for field strength when setting up or installing IL systems.
• Need to check IL systems regularly (field strength, connections, wire fraying, etc.).
• Need more durable IL systems (portable and permanent).
• Need affordable Inductive loop systems for small organizations and community groups, community groups.
• Many applications for inductive loop systems (e.g. service counters, cars, home environments, ticket windows, taxis, elevators, etc.) have not been explored (a few exceptions were cited). 

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2. State-of-the-Practice (current technology)

• IL systems are very useful for large meetings (e.g. church)
• IL systems do not support multiple communication channels (e.g. like multi-frequency FM systems).
• IL systems are low cost relative to FM and IR based systems
• IL systems (permanently installed, not portable) can be designed to have very little signal spillover (2 to 3 meters outside of the loop).
• Lack of confidentiality - no practical way of completely eliminating all inductive field spillover (there is "a way" to stop spillover however, it is not cost effective)
• Sound level (from hearing aid) varies directly with inductive field strength.
• Inductive field strength (as received at T-coil) is not always uniform within looped area.
• IL systems (properly designed and installed) have fairly uniform field strength within the looped area. Your position within the loop should not affect signal strength.
• Inductive loop systems are unobtrusive and cost effective relative to infrared and FM systems - even if you need a separate receiver.
• Portable IL systems seem to take longer to set up than portable IR or FM systems.
• IL systems need to be customized for each location and application.
• Performance is susceptible to changes in the environment - inductive loop systems are more affected by what "other people" have done to the environment (changes to lighting, furnishings, room dimensions, etc.) then are IR and FM systems.
• Structural beams (in buildings) can distort the inductive field, generally not a problem for IL systems that are properly designed and installed.
• Some inductive systems use "3D mats" rather than loops. These systems produce more complex (3-dimensional) inductive fields. For these systems, head (T-coil) orientation is much less critical to signal reception.
• 3D mats cause sound distortion effects. Persons with normal hearing are not satisfied with the sound quality of IL systems using 3D mats.
• T-coils in hearing aids are an inherently small and portable receiver.
• Many hearing aids (BTE and others) already have built-in inductive receivers (T-coils).
• Most hearing aids (especially smaller devices) lack a receiver (T-coil).
• Some BTE hearing aids have 3-position T-switches (settings: hearing aid microphone only; T-coil only; both)
• Hearing aids are generally designed to respond to microphone-generated signals. T-coil generated signal differs from the microphone signal. This problem can be addressed by a multi-memory type approach (i.e. T-switch setting selects processing mode for microphone or T-coil).
• Voices simultaneously picked up through the hearing aid microphone and hearing and T-coil (from a neck loop, silhouette or phone handset) are difficult to comprehend.
• You can't use your hearing aid T-coil to listen to a phone while inside an active loop.
• It is difficult (coil size, orientation) put receivers (T-coils) into smaller (ITE, ITC, CIC) hearing aids.
• Receiver (T-coil) sensitivity is dependent upon its size. For hearing aids with built in T-coils, the size of the receiver is limited by the size of the hearing aid.
• Receiver (T-coil) orientation (head orientation) relative to the inductive field affects signal reception. The head position effect is a receiver (T-coil) issue, not a loop issue.
• T-coils pick up any magnetic field in the room (receivers are not tuned). Using T-coil near a computer can be problematic.
• T-coils receive their input from telephone handsets, silhouette and neck loops for FM and infrared (IR) receivers.
• Many newer telephones seem to provide poor signal quality to the T-coil.
• Basic inductive loop receiver (a hearing aid with a T-coil and without a microphone) sells for about 82 pounds in England. A separate inductive loop receiver is less expensive than an infrared or FM receiver.
• Inductive receivers are very cheap - a hand held receiver can be built for $25.
• FM and IR receivers with inductive neck loops are too large and are uncomfortable during vigorous physical activity (e.g. dancing, aerobics, etc.)
• Silhouettes (small induction coils) are less obtrusive than a neck loop and generate a very high field.
• IL systems are simple to maintain (e.g. permanent loops are very durable when properly installed, no maintenance for T-coil receivers)
• IL systems (permanent or portable) are often poorly installed - need to calculate loop area, measure and calculate field strength, know applicable standards, and check what the field strength should be.
• Wires becoming frayed or disconnected is a common problem for portable IL systems.
• Poor IL system performance is often due to poor installation.
• Sound contractors often improperly install IL systems.
• It isn't necessary to hire a professional installer - a person can be trained (in one-half hour) on how to "double check the loop system." The main concern is field strength.
• Need to properly match amplifier to loop.
• Inappropriate amplifiers are often purchased separately and used to drive the inductive loop.
• Amplifiers used to drive inductive loops often do not meet standards.
• Amplifiers selected to drive the inductive loop (e.g. audio amplifiers) are often inappropriate.
• Manufacturers sometimes make inaccurate performance claims for their amplifiers.
• There aren't many amplifier manufacturers. Limited choice of amplifier performance and features.
• Persons with severe hearing loss often have higher quality hearing aids with T-coils.
• Persons with greater hearing loss often have BTE hearing aids with T-coils. Persons with less severe hearing loss often use smaller ITE or CIC hearing aids that lack T-coils. Therefore, persons with more severe hearing loss are more likely to use and benefit from inductive loop systems.
• Most hearing aids being used in the United States lack T-coils (perhaps 30% of U.S. hearing aids have T-coils)
• Many public venues (e.g. auditoriums) that adhere to ADA regulations only loop certain sections. Hearing impaired individuals may feel separate (different) from other individuals.
• Entire looped area is hearing accessible.
• Segregation when only a portion of a room is looped, persons using inductive loop systems may feel segregated and isolated.
• Building power lines can generate interference. However, when power lines are properly installed there should be almost no interference.
• Power lines operate at 60 Hz. Power line harmonics (i.e. 120 Hz, 240 Hz) are picked up by inductive receiver (T-coil)
• Lighting controls can cause interference (e.g. Scars/ lighting controls).
• If inductive loop systems did not exist, who would be affected? Environments or situations where you can't (conveniently) issue IR or FM receivers to people (e.g. ticket windows, answering machines, bus/cab, etc.)
• IL systems are not the best choice for "tour guide situations" (e.g. museum displays, self-guided tours, etc.). FM or IR based ALS are currently more suitable for these applications.
• Small inductive loops systems are available for service counters and teller windows (e.g. Audi product)
• IR systems are making big inroads on IL markets in Europe.
• Inductive loops could be installed in swimming pools (and other wet environments) but receivers (hearing aid T-coils) are not waterproof.
• IL systems are great for educational facilities and auditoriums where there might only be one or two hearing aid users - very cost effective.
• Talking Lights - new technology that replaces the standard fluorescent ballast with "special" ballast. Talking Lights eliminates the infrared interference problem of fluorescent lighting. May be "perfect solution" where fluorescent lighting is already installed. Concern was raised that lights are turned off for presentations - suggestion made that projector itself could be used as a Talking Light. System is not affected by broad daylight, as long as fluorescent lights are on. Talking Lights uses the 60 Hz AC power supply as a system clock.
• Metal cage problem - buildings constructed in the United States have far more metal than those in the United Kingdom. Solution - use different loops designs for different installations - Amptronics
• International standards specify the basic setup/installation requirements for IL systems - not highly technical.

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3. Needed Technology (refinements, innovations)

• Receiver (T-coil) should fit (with proper orientation) into smaller (ITE, ITC, CIC) hearing aids.
• Receiver (T-coil) performance should not be sensitive to its orientation relative to the inductive field (e.g. 3D T-coil receiver. Two or three coils "combined into one." Practically, you should be able to get away with two coils - one flat, one vertical. Use microprocessor to process signals from multiple coils.)
• Improve receiver sensitivity by increasing coil size (e.g. by embedding in hearing aid body), perhaps change core material
• Smaller hearing aids should incorporate T-coils with 3 settings (T-coil, microphone, both).
• Hearing aids should have receivers (T-coils) that can be tuned to specific inductive loops. This would allow a number of loops to be run in the same area - analogous to FM systems with multiple, selectable frequencies).
• Receivers (T-coils in hearing aids or separate units) should have the ability to distinguish frequency.
• Receivers (T-coils) should sense field strength and normalize received signal appropriately (perhaps a reference signal could be transmitted from inductive loop).
• Common inductive noise (e.g. 60 Hz and harmonics) should be filtered out at the receiver (T-coil) level (e.g. filtering out 60 Hz hum is not difficult - practical solution can be found on Motorola website).
• Receiver should be shielded from high frequency interference.
• Hearing aids with programmable T-coils characteristics.
• Inductive loops (mats, or equivalent) should be simple and foolproof for non-technical users (e.g. drop loop onto floor; plug it into the amplifier; system senses and auto-adjusts field strength).
• Portable inductive loop systems should be prefabricated, reliable and have predictable performance
• Inductive loop systems (permanent and portable) should have a modular design to allow for easy expansion.
• Should take advantage of signal spillover to configure for larger environments (note: good performance with the spillover signal may require a more advanced receiver).
• Should integrate field strength meter into the inductive loop system; provide feedback to the loop amplifier to auto-adjust field strength.
• IL amplifiers should self-adjust based upon loop impedance.
• IL systems should have general-purpose amplifier plus a separate loop driver unit.
• Loop driver unit could be an intelligent adaptor for general-purpose amplifiers.
• IL systems should produce high quality sound (i.e. no distortion, as perceived by hearing aid user or non-hearing impaired person using headphones)
• A room's size, shape and architectural features should be the criteria for the proper design and installation IL system-not a limitation.
• Increase demand for advanced inductive loop systems. Make sure these systems accommodate the needs of persons with and without hearing impairments (e.g. good sound quality is necessary if a person with unimpaired hearing is listening to the philharmonic orchestra).
• Audiologists should be educated to the benefits of the IL and so they can prescribe / recommend hearing with T-coils to their patients.

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4. Barriers (to obtaining or developing technology)

• Lack of T-coils in majority of hearing aids sold in United States
• Lack of consumer understanding / education. Consumers don't understand the concept or benefits of inductive loops and T-coils. They therefore don't demand T-coils when purchasing their hearing aids.
• Audiologists (appear to) have a perception that T-coils are expensive and that IL systems are not effective or readily available. For this reason they do not recommend T-coils to their clients. Actually, T-coils in BTE are inexpensive and IL systems are available and cost effective in some areas.
• Many audiologists don't even try to sell BTE hearing aids with T-coils.
• Lack of consumer confidence in T-coil performance. Unpredictable performance. (Note: T-coils are mostly present in the hearing aids of persons with severe hearing impairments. Performance expectations may be unrealistic. T-coil performance is dependent upon the quality of IL system installation, telephone quality and many other factors.)
• Segregation - persons using T-coils need to sit in looped region. Within this region, they must sit in a location where they get the best reception. This may not be where they would prefer to sit.
• Inductive loops are not common (e.g. through the community) - until that changes will be difficult to sell hearing aids with T-coils.
• Lack signage on buildings indicating when an IL system is installed and accessed.
• Lack signage on telephones indicating when they are T-coil compatible.
• Lack information / signage at the point of sale indicating when phone is T-coil compatible.
• 3D T-coils require three loops and these loops must be smaller in order to fit in the same hearing aid volume. You need more amplification to pick up signal and therefore more power to provide the amplification.
• Incorporating 3D T-coils into hearing aids increases their cost (note: most participants thought that the cost impact would be very minor).
• Reducing T-coil size (for smaller hearing aids) reduces its sensitivity to the signal and increases its sensitivity to electromagnetic interference / noise.
• T-coil is not going to fit as hearing aids get smaller and smaller.
• Hearing aid speaker produces a field that can be picked up by the hearing aid T-coil.
• Initial installation of IL systems is labor intensive and costly.
• IL system installers are not always competent.
• Difficult to get correct match between amplifier and loop - requires highly knowledgeable person to do that.
• Difficult to set up portable loops correctly. Need to know the size of looped area and use the right amplifier size. Need high level of technical skill - requires appropriate technology, tools, and expertise.
• Power wiring layout in new buildings makes no allowance for the future installation of inductive loops. Significant source of interference.

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5. Technology Sources

• An application for those who don't need or wear hearing aids (receiver in the shape of the T-Coil (used by secret service and news anchors).

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