Articles

Hearing aid manufacturers and audiologists de-emphasize telecoils and volume controls

by John Woodgate HonFInstSCE

I lost a hearing aid, almost certainly dislodged by a virus mask. The replacement offered didn’t have a telecoil ‘because that’s replaced by Bluetooth and WiFi’!

A couple of years ago, it looked as if telecoils were really going to be extinct, but, probably because of the strong and effective advocacy for hearing loops in the Americas, hearing aid manufacturers are now offering a limited number of more costly models with telecoils, but almost all of their ranges have Bluetooth.

The web site of one well-known manufacturer includes this gem:

‘With Telecoil (T-coil) that offers access to FM systems using a neckloop receiver’

Luckily, there seems no move from the NHS to eliminate telecoils, but even that needs vigilance.

It seems to me that there is serious wrong-thinking by the hearing aid manufacturers, partly prompted by their brainwashing of the clients to believe that it is essential for a hearing aid to be invisible, or nearly so. Contrast Bluetooth earpieces and wireless earbuds! Telecoils can’t be made very small indeed, so if there has to be room for Bluetooth and battery-charging circuits, the telecoil has to go.  What happens if the client, e.g. me, is too deaf to use a smartphone, so Bluetooth is useless? What about all the people who have been using a hearing loop system in their place or worship. theatre or cinema (or anywhere else) for many years?

Someone there is seriously mixed-up!

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What happens if the client, e.g. me, is too deaf to use a smartphone, so Bluetooth is useless?

‘Oh, loops are out-of-date’.  Well, loops (and I) date from about 1937, whereas the aeroplane dates from 1903 and the motor car from the 19th century. Are we abandoning those as being even more  ‘out-of-date’?

Another issue is that hearing aids without a user-adjustable volume control have been introduced, and websites don’t even mention whether there is a volume control on a particular model. If the volume is set by the audiologist, that setting applies only to those hearing conditions. This is not a pure ‘hearing aid issue’. There are often wide differences in gain and frequency response between the M (microphone) and T (telecoil) modes of operation. While IEC 60118-0 has text on this issue, it’s very weak:

The frequency response curves measured acoustically and magnetically can differ significantly because of the differing input transducers, but in most cases they should not intentionally differ.

Moreover, the sound level varies from place to place in an auditorium, and so does the magnetic field strength – it meets the 400 mA/m requirements only in some places – this is inevitable. So the user really must be able to adjust the volume to a comfortable level. 

Can ISCVE and its friends in IHLMA seek to turn the tide on these issues?