Many people are still disappointed, because getting a hearing aid does not guarantee a return to 'normal' hearing as they once enjoyed. It gets even worse when they pick up the phone and notice that it does not work well together with their hearing aid. "We have all the technical elements needed for successful integration of hard of hearing people in the working place and of course for giving them the capabilities to communicate on the phone", said one of the participants in the recent HÖRKOMM workshop in Berlin. "But the issue is that people are not informed enough about what is technically feasible today, they do not know who to ask, and then of course there is also the problem of financing it."
How do phones work with hearing aids? And what is the M- and T-rating?
In general, hearing aids use their microphone to pick up sound waves in the air and convert the sound waves to electrical signals. The signals are amplified as needed and converted back to audible sounds for the user to hear. The quality of this acoustic coupling is qualified for phones by their M-rating (M=microphone). The hearing aid's microphone, however, does not always work well in conjunction with telephone handsets. The acoustic connection between hearing aid and handset can be distorted and surrounding noise can interfere.
One of the most common technologies of avoiding these problems and making phones work with hearing aids is inductive coupling by using a telecoil. The telecoil in the hearing aid converts the magnetic fields generated by telephones into sound and allows the volume control of a hearing aid to be turned up without creating feedback or "whistling" on the phone. The higher the T-rating of the phone, the better they work with hearing aids in the telecoil setting. For the hearing aid user it is important to verify that the telecoil in the hearing aid is activated and that the device is set to telecoil mode. Telecoils are also used to interface with other assistive devices and an additional benefit is that they can easily be made available in public spaces. Places such as railway stations, service kiosks, churches and many tourist attractions have installed induction loop systems that in conjunction with the telecoils, magnetically transmit sound to hearing aids and cochlear implants.
Mobile phones with M3/T3 rating comply with the US standard for hearing aid compatibility and the best currently available reach M4/T4 ratings. However, the subjective hearing of the user as well as his/her hearing environment play a major factor and some users may feel that they can better communicate with a phone that has a lower M/T rating. The only way to tell which mobile phone will work best for a person with hearing aid is to test the devices together in different settings.**
A newer technology for transmitting the audio signal directly into the hearing aid is bluetooth. There are two issues with this technology: it necessitates the pairing of devices and bluetooth is more power intensive (as compared to hearing aids) than the hearing aid which shortens battery life. The advantage is that bluetooth is an industry standard. Some of the hearing aid makers are also experimenting with near field communications (NFC) which would have the potential to become a standard for the interface between hearing aids and other audio devices, including the mobile phone.
Elaborating guidelines for the successful integration of the hard of hearing in the work place
HÖRKOMM is a project financed by the German Federal Ministry of Labour and Social Affairs with the objective of developing guidelines for the successful integration of hard of hearing employees at the workplace. In the framework of this project, a workshop took place on 4 November 2013 in Berlin, Germany bringing together representatives from the hard of hearing community, hearing aid and mobile phone makers, federal inclusion bureaus, and hearing aid technicians, to discuss how to make telecommunications more accessible for the hard of hearing. The conclusion was that we have the necessary technological means but that there is an overwhelming lack of information among users and hearing aid technicians. A further barrier is of course the financing of the technical solutions.
* All participants at the HÖRKOMM workshop on 4 November 2013 in Berlin, including hearing aid technicians, hearing aid manufacturers as well as several representatives of associations for the hard of hearing in Germany, seemed to agree on this statement.
** Information on M- and T-ratings is available only the GARI database only for models marketed in the US.