Intervention and the hearing-impaired child--an evaluation of outcome

Hearing aid use in Finnish children--impact of hearing loss variables and detection delay

OBJECTIVE

The aim was to study the factors contributing to the mode of hearing aid use in children, with special emphasis on hearing loss variables and detection delay.

METHODS

The subjects were 328 children and adolescents (58.5% boys, 41.5% girls) aged 1-18 years with hearing loss of > or =30 dB HL in the better ear fitted with hearing aid(s). The study was cross-sectional analysing the mode of using the aid binaurally/unilaterally or not at all.

RESULTS

The children with hearing-impairment ranging from 50 to 90 dB HL used more regularly their hearing aids. In the subjects with hearing loss > or =80 dB HL the presence of measurable hearing threshold at 4 kHz related significantly to the acceptance of amplification (p=0.027). In 19% of the subjects hearing aid was discarded. Bilateral amplification was used in 38%. Unilateral use was the prevailing mode (44%). The younger the children (p=0.000) and the worse their hearing loss (p=0.008), the more regular their bilateral use was. Early detection of hearing loss and early hearing aid fitting promoted binaural hearing aid use (p=0.004). A marked asymmetry in pure tone thresholds was a significant audiological reason for fixed unilateral hearing device use (38%, p=0.001).

CONCLUSIONS

The study shows that early detection of hearing loss and early habilitation of hearing increase bilateral use of hearing device and decrease the number of nonusers. Furthermore, residual unaided hearing at 4 kHz significantly improves the use of device.

Early natural auditory-verbal education of children with profound hearing impairments in the Federal Republic of Germany: results of a 4 year study

Early education of children with hearing impairments has been carried out in the FRG for the past ca. 40 years using a variety of different educational concepts. One of these concepts is the natural auditory-verbal approach. By supporting the development of hearing, even amongst children with profound hearing impairments, it stakes the claim of being capable of initiating the children's development of natural auditory-verbal skills, which are then comparable to those of children with normal hearing. Nevertheless, to this date, no empirical study of the approach and its measure of success had ever been undertaken. During the course of this study, the measures involved in a hearing-oriented system of early education were comprehensively examined. The analysis was performed on the advancements made in the natural auditory-verbal skills of infants suffering a loss of hearing of 90 dB or more and who were educated in such a way. The study comprised 103 children with profound hearing impairments, who were younger than 24 months old at the time the study began. Their respective developments were followed in three separate surveys between 1996 and 1998. The results were analysed using bivariate as well as statistical correlation methods. The children's development is impeded by such factors as late initial diagnosis; delayed supply of hearing aids and late commencement of early education; poorly-adjusted hearing aids and short periods of wearing them. A system of early education that is only to a very limited degree hearing-oriented, and a family environment where little is spoken and where the child's auditory disability receives only scant attention, may also play a part. On the other hand, under favourable circumstances, even children with profound hearing-impairments may attain a development level of natural auditory-verbal skills which corresponds to that of children who can hear well-perhaps with a certain time-delay, and certainly involving a greater effort on the part of the children, but basically, in the same natural way and with a very similar quality of results. The early education system must urgently be improved by the introduction of screening for new-born infants. As far as devices are concerned, the cochlear-implant (CI) will very soon be standard equipment for infants with profound hearing-impairments. Within institutional facilities, there is a broad consensus that the goal of these measures consists of the development of speech communication skills in children. In practice, however, the strategies for realising this goal are not only very different, but also, partly, have downright counterproductive effects.

The effect of neonatal universal hearing screening in a health surveillance perspective--a controlled study of two health authority districts

The contribution describes the effect of a neonatal hearing screening program in terms of estimated prevalence rate of congenital hearing impairment and age at identification in two five-year cohorts born between 1990 and 1994 as a function of health authority districts (HADs). In addition, identically defined five-year birth cohorts from 1970 to 1974 and 1980 to 1984 living in the same HADs evaluated previously are used in the analysis, offering longitudinal data. In 1990 a non-targetted neonatal hearing screening program based on EOAE was introduced in the County-HAD, whereas the City-HAD continued its child hearing health surveillance program unchanged. Assuming an unchanged prevalence estimate of 1.5 per 1000 of congenital or early acquired (i.e. neonatal period) hearing disability, i.e. > or = 25 dB HL for the better ear at 0.5-4 kHz in both HADs, an underestimate of 68 per cent in the City and of 20 per cent in the County, respectively, was found at the time of data collection (January 1995). Significant longitudinal improvements in the early identification from the 1970-1974 cohort compared to the 1980-1984 cohort has been demonstrated, but the improvement in the proportion of children identified as a function of both 6 and 12 months of age in the 1990-1994 cohort is significantly greater, showing a median age at identification of 11 months in the County-HAD. The cross-sectional and longitudinal comparisons between the HADs imply that a neonatal universal hearing screening program with a 20 per cent coverage may add significantly to the early identification of children with early-onset hearing impairment.

Rehabilitation of hearing-impaired children: intervention and outcome

A cohort of 72 hearing-impaired children of a median age of 9.7 years, range 4.3-13.9, born during 1980-1990 and living in the health district of Copenhagen City was examined cross-sectionally in order to evaluate the interval from identification to the initial fitting of hearing aids (HAs) and children's use of HAs. As measures of outcome, the use of HAs at 1, 6, 12 months after fitting, and at the time of data collection was assessed along with the primary language of each child. One month after the fitting, 53% of the total sample used the HAs > 8 h/day, and no significant longitudinal changes in the proportion of time-related use were found. 56% of the children stayed in the same user category during the years, while the rest either increased (25%) or decreased (19%) the use of amplification from 1 month after fitting to the time of data collection. Children with better ear hearing level (BEHL) 0.5-4 kHz between 60 and 89 dB used the HAs significantly more than those with mild or profound hearing impairments, whereas age at onset (congenital, acquired, age at onset unknown) and age at intervention were unrelated to use of amplification. 72% of the children were oral, while 25% were manual (unknown 3%), and no differences in the use of HAs were found between these two groups. A subdivision of congenitally hearing-impaired children according to BEHL 0.5-4 kHz below/above 75 dB demonstrated a significantly larger proportion of manual children in the poorer hearing group despite a significantly younger amplification age. It is concluded that age at intervention is unrelated to primary language, although the number of children precludes dependable conclusions.

The causes of profound hearing impairment in a school for the deaf--a longitudinal study

The study was aimed towards an evaluation of the causes of hearing loss in children attending the School for the 'Deaf' in Copenhagen in 1993-4 in comparison to causes evaluated 10 and 40 years previously (Arnvig, 1953; Holten and Parving, 1985). The 124 children attending the school in 1993 represent 0.04% of the age-matched target population of 312,715. A more detailed evaluation of two comparable cohorts born in 1969-77 and 1979-87 demonstrates a significant increase of children attending this type of school from 0.03% to 0.05% within a 10-year period, while a comparison between 1953 and 1993 demonstrates a reduction from 0.07% to 0.04%. The longitudinal evaluation of the causes of hearing loss showed a significant increase in the frequency of congenital inherited hearing impairment from 29% (1953) through 33% (1983) to 43% (1993), whereas a significant reduction of about 17% in the frequency of acquired deafness due to chronic otitis media was found. Between 1953 and 1993 a minor reduction (2%) in post-meningitic acquired hearing impairment was found, between 1953 and 1983 there was a significant increase in prenatal infections, compared with a decrease of 6% between 1983 and 1993. It is concluded that significant changes are found both in the prevalence of children referred to the school and in the factors causing severe to profound hearing impairment in children. Continuous recording of, and improvement in, diagnostic classification is necessary to obtain preventive measures.

Congenital hearing disability--epidemiology and identification: a comparison between two health authority districts

The objective of the present study was to describe some epidemiological aspects of congenital/early acquired (i.e. in the neonatal period) hearing disability (CEHD) in children born between 1980 and 1990, living in two separate health authority districts, i.e. the Copenhagen City/County; in addition, to evaluate the age at identification of the children, the persons raising suspicion of the hearing loss and the pattern of referral; finally, to compare some epidemiological aspects and the age at identification of similarly defined cohorts of children, born 1970-80. Thus the evaluation can be considered as an audit of the primary health care sector concerning children with CEHD. An identical prevalence rate of CEHD was demonstrated, i.e. 1.5/1000 with a better ear hearing level average at 0.5-4 kHz > or = 25 dB (BEHL 0.5-4 kHz) in both regions and unchanged from 1970-80. The median age at identification in the total cohort was 16/18 months in the City/County, respectively, demonstrating a significantly earlier identification of at-risk children in the County with the opposite pattern in the City. The parents were the first to raise suspicion of their child's hearing disability in 50%/57% in the City/County and only minor differences in the pattern of referral was found in the two regions. The frequency of at-risk children among parents/professionals who first suspected the CEHD showed no significant differences; however, the BEHL 0.5-4 kHz in the children was poorer in the group of parents who first raised the suspicion when compared with the group of professionals. Thus the BEHL 0.5-4 kHz is of significance for the age at identification and for the person raising the suspicion of CEHD. Although an improvement in the early identification of CEHD has taken place, when comparing the 1970-80 cohort and 1980-90 cohort, it is concluded that children with CEHD are identified with a substantial delay and that the line of information both concerning high-risk criteria and general information should be continued and intensified towards both parents and professionals.

Training and employment in hearing-impaired subjects at 20-35 years of age

This study was undertaken in order to evaluate the training and the employment situation in a cohort of hearing-impaired subjects born between 1955 and 1970. A sample of 288 persons was collected from 33,352 consecutive patients with hearing thresholds > 20 dB HL in at least one pure-tone frequency (250-8000 Hz) in one (right/left) ear and all living in the city of Copenhagen at the time of data collection. The total sample of 288 persons was divided into two groups according to age at onset of their hearing impairment: group 1 comprised 165 persons with congenital/early acquired hearing loss (before 2 years of age); group 2 comprised 123 subjects with acquired hearing loss (after 2 years of age), acting as a reference group. A questionnaire was mailed to all 288 subjects meeting the inclusion criteria, achieving 218 responses (76%). The questionnaire evaluated the educational and employment situation and revealed significant differences, training within crafts being more common in group 1 in contrast to training at university level being more common in group 2. A frequency of 31%/29% respectively of unemployment at the time of the questionnaire was found in the two hearing-impaired groups, compared with 12% in an age-matched background population. A subdivision according to hearing thresholds indicated that the degree of hearing loss is of importance for education at university level. A question concerning general well-being showed that the majority of hearing-impaired persons, irrespective of age of onset of their hearing impairment, are satisfied with their life.