Hearing loss in the UK

The term ‘deafness’ has many connotations and although one individual may not consider himself deaf, the rest of his family may be at their wits’ end because of an overloud television or a failure to hear the doorbell or telephone.

Some more precise terminology is required not only to be able to assess the extent of the problem but also to allow appropriate resources to be allocated to those groups most in need. The terms ‘hearing impairment’, ‘disability’ and ‘handicap’ have been used for many years to help provide a sensible framework for discussions between those groups with deaf interests at heart and the various government agencies. These terms are under review at present because they may be thought to be politically incorrect.

HEARING IMPAIRMENT

Hearing impairment is a number in decibels obtained from a measure­ment known as the pure-tone audiogram (see page 26). It is calculated for each ear as the average hearing level for several different frequencies. For many purposes, industrial deafness claims or war pension claims, for example, the hearing levels in decibels at one, two and three kilohertz (1, 2 and 3 kHz) are averaged. This measure tends to underestimate both the severity of the hearing loss because noise damage tends to involve the higher frequencies (that is, 4 and 6 kHz first), and the impact of the loss on hearing in back­ground noise, which is the major complaint of most claimants.

The measure used by the Medical Research Council’s (MRC’s) Institute of Hearing Research (IHR), in their national survey of hearing completed in 1989, was the average at 0.5, 1, 2 and 4 kHz. The MRC felt that this was a more appropriate indicator because it gave a better prediction of the problems besetting normal people.

DISABILITY

Disability is the overall difficulty that a hearing impairment causes an individual in his or her daily life. Examples are specific, such as being unable to hear properly in back­ground noise; finding the television and radio difficult to understand; and not hearing the door bell, the telephone or the ‘ping’ on the microwave oven that tells you that something is cooked. Disability can be rated on a scale of 0 to 100 per cent.

HANDICAP

Handicap is the effect that this disability has on an individual’s overall quality of life. An individual may become socially withdrawn because of difficulties in conver­sation and not wanting to be thought stupid. There can be major problems with education, employ­ment, within the family and with all interpersonal relationships. Handicap is a complex outcome and depends on the personality of the deaf individual, the support of those close by and the social environ­ment. At one extreme, a monk living in a monastery retreat may be profoundly deaf with an almost 100 per cent disability yet have no handicap whatsoever. Indeed the absence of distractions by outside sounds may be a positive benefit to his meditations. Was deafness a handicap to Beethoven’s musical output? Most individuals are, however, deeply distressed by the onset of more severe forms of hearing loss and deafness causes them a major handicap in their lives. Everything changes for them and their families.
In 1989 the Census office looked at the various self-reported disabilities across the nation. Although ‘mobility problems’ were the most common, ‘hearing difficulties’ were the second most common disability, affecting seven million of the population.

The IHR undertook a national study of hearing. Some 50,000 questionnaires were sent asking people for their assessment of their own hearing, tinnitus and the use of the NHS for assistance. It was found that young people tended to overrate their hearing disability whereas elderly people consistently underrated it. Thus, an extensive audiometric survey was performed to assess the prevalence – that is, the total number of affected people in the population at any one time – of the severity and different types of hearing loss. The hearing impair­ment in the better hearing ear was used as a predictor because it was felt that this was a better indicator of the overall disability.

The extent of the problem is difficult to comprehend. Sixteen per cent of the adult population had average hearing at 0.5, 1, 2 and 4 kHz of 25 dB or worse in the better ear. Nearly 90 per cent of these losses were sensorineural in origin. As the losses get more severe there is an increase in the number with a conductive element to the loss. The data also showed that young people had relatively few problems as a group, but that, once past the age of 50, the prevalence increased rapidly indicating that most deafness is acquired. One in three of the total number with hearing impairment was over the age of 80.

Thus, about one in seven of the population has some problem – hence the title of the excellent house magazine of the Royal National Institute for Deaf People (One in seven). These figures are probably applicable to most Wester­nised societies and include those who are born with a severe hearing impairment. The general figures are that about 1 in a 1,000 children is born with hearing levels worse than 50 dB and that each year another 3 people in every 10,000 becomes severely deafened, usually as a result of meningitis.

Overall, the figures show that there is a massive core of disability that requires a huge resource in financial terms for aids for hearing-impaired individuals, in commitment to equal opportunities and in human involvement in minimising handicap.