The mobile telephone operators are using a variety of labels to describe their new digital mobile telephones. The systems vary in power, radio frequency and type of use, but all operate on essentially the same digital principle. Soon cordless digital telephones will be available. These also work on the same principle, but at a low power. It is possible that they may cause interference when held close to a hearing aid, so again, they should be tried with the hearing aid before purchasing.
Hearing aids are too intricate and there is no space available for modifications.
Hearing aid manufacturers are investigating how to design new hearing aids that are more immune to the interference. Technical Background Conventional mobile telephones use analog technology, with just one conversation on each radio frequency at a time. As there are only a limited number of radio frequencies available, this means that the demand is greater than supply and this keeps the cost high. The digital systems, however, squeeze up to 8 conversations onto each radio frequency, without the different conversations being aware of each other. This makes the radio 'air space' much cheaper.