Ena Thompson of Steele Road, Isleworth, was provided with analogue hearing aids, which she can no longer hear with or adjust since she does not have much feeling in her fingertips, her son says.

The elderly patient has been placed on a waiting list for a digital aid and has been told she is 142nd in line. Her son, Mr John Thompson, has made requests to the aural department of the hospital in the hope that it will provide an aid sooner.

He said: "All my requests have been ignored. The result of her not being able to hear is that she is slipping deeper and deeper into depression. She does not feel able to meet with even close relatives and can not watch TV or listen to the radio.

"When anyone calls, her main concern is that they will leave soon because the strain of trying to hear is so tiring. Her main occupation is sitting in a chair and picking her fingers. She has become totally isolated.

"The rest of my mother's life is most easily measured in months. I had hoped that these could be relatively happy ones but it would appear that they will be grim ones with an eventual merciful release from silence and isolation."

The hospital says that Mrs Thompson was sent an appointment by the hospital on March 7 asking her to attend to be assessed for her digital hearing aid on March 21. However, she did not attend and the department did not receive any contact.

A spokesperson said: "There are currently 979 patients on the hospital's waiting list for a digital hearing aid. Following a recent call from her family, Mrs Thompson, was put back on the waiting list at 142 this month.

"When patients do not attend their appointment without good reason they are usually put at the bottom of this list but Mrs Thompson was given a higher priority."

The digital hearing aid project is part of a five-year national programme across the NHS to move hearing aid users from analogue to digital hearing aids. As a result of the numbers of patients involved, waiting lists exist in many hospitals.

West Mid is currently using agency staff to work through the waiting list but there are financial constraints.

By Sarah Woods