Biomedical subjects

A Parving

Publications and source records attributed to A Parving.

At least 55 records · Page 3Linked to original sources

PubMed1994

Is there a relationship between the acoustic occlusion effect and the sensation of occlusion?

The objective of the present investigation was to examine the relationship between the acoustic occlusion effect and the subjective occlusion sensation when using ear moulds. The material comprises 45 subjects (19M and 26F, at a median age of 76 years, range 38-88 years) subgrouped according to the classification of their hearing disorder into two group: N = 22 subjects with conductive hearing loss (1); N = 21 subjects with sensorineural hearing loss (2). The side effects caused by an ear mould were evaluated at an interview, based on a structured questionnaire, two months after the hearing aid fitting. The comparative investigation showed that when the outer ear canal was occluded with an ear mould there were no significant differences between the two groups of subjects in the frequency of sensation of occlusion, in the sound quality of environmental sound or own voice, in hearing problems when chewing, or in ventilation problems. Neither were significant differences in the magnitude of the acoustic occlusion effect present between those answering yes and those answering yes and those answering no to a change in the sound quality of own voice in the group with sensorineural hearing loss. Although the number of subjects is limited, it is concluded that no relationship exists between the acoustic occlusion effect and the perceived sound quality, thus leaving no physical basis for the claim that this side effect is caused by an ear mould.

Adult↗

PubMed1994

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.

Adolescent↗

PubMed1994

An audit of hearing aid quality in Denmark. II: Type of defects.

In this investigation the type of defects in hearing aids (HAs) is described, and the stability of HAs is evaluated, based on prospective longitudinal data over an observation period of 2 years. An exchange of information between the Danish national hearing health service and hearing aid manufacturers, representing the private sector, demonstrates that overall external components to which the HA-user has access, are frequently defective. However, with time, internal components, to which the HA-user has no access, are frequently defective within the first year of use, whereas external components malfunction significantly more frequently after 3 years of use. Among the dispensed hearing aids, 11% were defective at the fitting, indicating insufficient quality control by the manufacturers. A prospective longitudinal investigation of 1141 defective HAs revealed that 12% of behind-the-ear HAs become defective within the first year of use, exhibiting the greatest stability. After 2 years of use, all in-the-canal HAs are defective, while only 33% of the in-the-ear HAs remain intact. It is concluded that the established exchange of information between the public and private sectors offers valid information on the quality of HAs; that the quality and stability of HAs is insufficient; and that the quality should be improved, (based on international criteria).

Correction of Hearing Impairment↗

PubMed1993

[Congenital hearing disability among children in Copenhagen].

The survey describes the detection, identification and aetiology of congenital/early acquired (i.e. neonatal period) hearing disability in a well-defined cohort of children, living in the Copenhagen area (Copenhagen City and County). The effect of intervention programmes is also mentioned. The children's age at identification can be considered as an evaluation of the quality of hearing screening aimed towards the detection of children with congenital/early acquired hearing disability, while the results of the aetiological evaluation reflects the quality of the diagnostic evaluations performed within paediatric audiology. The prevalence rate of 1.5/1000 of congenital/early acquired hearing disability for children born during 1980-1990 is unchanged in comparison to the period 1970-1980. An improvement in the detection of children with congenital/early acquired hearing disability is found, the identification is, however, still delayed in both children at risk and not-at-risk of hearing disability. The parents are most frequently the first to raise suspicion of their child's hearing disability, but very seldom apply to the audiological department without a referral from the primary health care sector. A change in the aetiology of congenital/early acquired hearing disability has taken place within 1980-1990, which can be ascribed to the reduced frequency of foetal rubella infection, while the frequency of inherited hearing disability has increased. The outcome of intervention programmes, evaluated by means of type of school, education, and employment situation is briefly described in relation to the social consequences of a hearing disability.

Child, Preschool↗

PubMed1993

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.

Age Factors↗

PubMed1993

Hearing disability in childhood--a cross-sectional and longitudinal investigation of causative factors.

This contribution describes and compares the causes of hearing disability in a cohort of children, born 1980-90, provided with hearing aids and included into the longitudinal surveillance programs of hearing-disabled children performed in two pediatric audiological units within the Copenhagen area. In addition the causes of hearing disability in childhood are compared with the causes found in a cohort born 1970-80, within the same geographical area, using the same criteria for hearing disability and diagnostic classification. No significant differences in the etiology of hearing disability were present in the two districts, and in the combined area prenatal causes accounted for 55% with inheritance (46%) being the most prominent cause of hearing disability. A significant increase in the incidence of inherited hearing disability among the prenatal causes from 69% in the 1970-80 cohort to 85% in the 1980-90 cohort was demonstrated, while a significant decrease in the incidence of foetal infection (i.e. rubella) from 27% to 9% within the two decades was demonstrated. No significant changes in the perinatal and postnatal causes were found from the 1970-80 to 1980-90 cohort, and although an improvement in the diagnostic procedures was found--i.e. a reduction from 26% to 20% in the incidence of unknown cause--the difference in the incidence of unknown cause is insignificant between the two decades. The investigation supports the need for continuous monitoring of the causes of hearing disability in childhood and supports the potential value of worldwide accepted criteria for etiological categories.

Child↗

PubMed1993

Observer variations in the evaluation of facial nerve function after acoustic neuroma surgery.

This investigation was performed in order to evaluate the observer variations in facial nerve function after surgery for an acoustic neuroma. From 1976-90, 507 patients were operated on by the same surgical team (M.T. and J.T.) using a translabyrinthine approach. One hundred and forty-four patients living in Copenhagen City and County were invited for interview and objective examination. Only 128 patients attended the interview and examination which were carried out by the same ENT physician. Data concerning observation of the facial nerve function only is presented. Its function was clinically evaluated (using the House and Brackmann (1985) grading scale) by two different observers i.e. the ENT physician and one of the surgeons. The patients were asked face-to-face with the ENT physician to estimate the degree of facial nerve function according to a 0-100 per cent scale. Comparing normal and abolished facial nerve function the judgments of the ENT physician and the surgeon agreed with the patient's own evaluation.

Adult↗

PubMed1993

Mixed solvent exposure and hearing impairment: an epidemiological study of 3284 men. The Copenhagen male study.

Animal experiments and human studies have indicated an effect on auditory functions from exposure to organic solvents. In this study the relationship between self-assessed hearing problems and occupational exposure to solvents was investigated in a cross-sectional design with 3284 participating men aged 53-74 years. Exposure to solvents for five years or more resulted in an adjusted relative risk (RR) for hearing impairment of 1.4 (95 per cent CI: 1.1-1.9) in men without occupational exposure to noise. Factors adjusted for were age, noise traumas, chronic middle ear infection and family history of hearing impairment. The prevalence of hearing impairment in men not exposed to organic solvents was 24 per cent and the attributable risk from solvent exposure was 9.6 per cent. Exposure for less than five years had no effect on hearing capacity. Occupational exposure to noise for five years or more had an effect twice that of solvents, RR: 1.9 (95 per cent CI: 1.7-2.1). In men exposed to both solvents and noise the effect of the latter dominated and no additional effect from solvents was found. A subsample of 51 men was examined with pure tone audiometry and 20 of 21 men who reported abnormal hearing also fulfilled an audiometric criterion for hearing impairment. In conclusion a damaging effect on hearing ability from long-term solvent exposure was found in the present study. The relative effect was moderate but with a high background frequency of hearing problems in the unexposed sample the absolute effect, ie attributable risk, was considerable and of both clinical and preventive importance.

Aged↗

PubMed1993

Epidemiology of hearing disorders. Some factors affecting hearing. The Copenhagen Male Study.

This epidemiological investigation reports on the results from a 10-year follow-up examination concerning hearing and factors known to cause hearing problems. In addition, an evaluation concerning the possible association between hearing impairment and factors affecting the state of health is reported. The original sample comprised 5,050 subjects, and at the present examination 3,387 (67%) males at a median age of 63 years (range 53-75) participated. An increasing prevalence of 30-40% of hearing problems was demonstrated with increasing age. A prevalence of 17% of tinnitus of more than 5 min duration was found; 3% indicated that their tinnitus was so annoying that it interfered with sleep, reading and/or concentration. The prevalence of tinnitus increased up to the age of 70, and seemed to remain constant thereafter. A significant correlation between experienced hearing problems and environmental factors causing damage to the hearing organ was found. Furthermore, a correlation between hearing problems and C3-S complement was found, but no correlations could be established between hearing problems and other blood groups. No correlation was found between cardiovascular disease and hearing problems except for minor circulatory problems, nor between hearing problems and hormonal diseases. It is concluded that the present study supports previous epidemiological investigations concerning the prevalence of hearing problems and factors affecting hearing. The association between hearing problems and C3-S complement, which to the authors' knowledge has not previously been reported, should be further evaluated. No association was found between hearing problems and other blood groups.

Age Factors↗

PubMed1993

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.

Adolescent↗

PubMed1992

Some aspects of life quality after surgery for acoustic neuroma.

This investigation was performed to describe some aspects of the quality of life in subjects after translabyrinthine removal of an acoustic neuroma, resulting in unilateral total deafness. Two hundred ninety-three subjects who had been operated on during 1976 through 1990 and who were living outside the Copenhagen (Denmark) City and County received a postal questionnaire, to which 93% (n = 273) responded: 118 men and 155 women with a median age of 58 years (range, 18 to 81 years). The median observation period from surgery to the questionnaire was 6 years (range, 6 months to 14 years), and the median age at operation was 52 years (range, 15 to 76 years). Among the subjects, 22% had received postoperative hearing rehabilitation with various types of hearing aids in the ear not operated on. In 62%, tinnitus was experienced in the ear with tumor before surgery, and at the time of the questionnaire, 49% experienced tinnitus in the ear operated on. Half a year after surgery, 56% still experienced dizziness. Sixty-four percent reported damage to the facial nerve in relationship to the operation. At the time of the questionnaire, 12% indicated a total loss of facial nerve function. No vocational consequences were found in 74% after surgery. Information concerning different symptoms related to surgery was insufficient in 29%, while the quality of information in relation to surgery was more satisfying. In conclusion, the study demonstrates that deafness, dysequilibrium, and reduced facial nerve function caused the most severe problems. Improved information to patients before surgery may reduce the frequency of negative experiences.

Adolescent↗

PubMed1992

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

The investigation was performed in order to evaluate the outcome of intervention in preschool age. The material comprises a cohort of 138 children, 76 boys and 62 girls, born during 1970-1980, living in the Copenhagen County at the time of data collection (1987), all suffering from predominantly congenital/early acquired hearing disability (i.e. hearing level greater than or equal to 35 dB HL for the average of 0.5-4 kHz on the better hearing ear). The type of school attended is used as a measure for outcome of preschool intervention. It was demonstrated that 49% attended normal class (speech), 21% attended special units (total communication), and 24% attended the school for the deaf (sign/manual). By subdivision the children (n = 75) with a hearing loss less than 75 dB HL attended normal class in 80%; 7% attended special units. The children (n = 63) with hearing loss greater than or equal to 75 dB HL attended normal class in 11%, special units in 33%, and school for the deaf in 52%. An early identification of the hearing loss was found to facilitate attendance of normal class in the group with a hearing loss less than 75 dB HL. Among the children at the school for the deaf 84% had speaking parents. The frequency of the causes of hearing loss differs significantly in the special units, when compared to the total cohort. It is concluded that the outcome of preschool intervention is related predominantly to the degree of hearing loss; that an early intervention in the group of children with hearing loss less than 75 dB HL facilitates the attendance of normal class; that the frequency of the causes of hearing impairment is different in the special units.

Adolescent↗

PubMed1992

Children younger than 4 years of age, referred to an audiological department.

This investigation was performed in order to evaluate why and by whom children less than or equal to 4 years of age were referred to the regional audiological department in Copenhagen: and in addition to describe the audiological investigation and the obtained results in relation to the relevance of the referral. One hundred and forty consecutive first time referred children, 92 males and 48 females, at a median age of 28 months, range 2-49, were included. Of them 71.4% were referred from the general practitioners or local ENT doctors, while only 9.3% were examined on the parents' self-request. The parents were the first to raise suspicion of a hearing loss in 60%, which differs significantly from the 32% correctly found in professionals. The rate of false positive suspicion was similar in the two groups. Forty-nine % of the referred children suffered from hearing impairment, predominantly due to otitis media with effusion. Only 9% of the children were able to perform a pure-tone audiogram. A frequency of 2.9% of children with congenital/early acquired hearing loss was found and a delayed identification demonstrated. The investigation shows that the parents are more efficient in their observation of children concerning hearing loss than professionals, and that the prevalence of "true audiological children" is so restricted that the pediatric audiological services should be centralized and form part of the health hearing service offered to the hearing-impaired. In addition was found that the special equipment and expertise needed for audiological evaluation in young children is used fairly relevantly.

Audiology↗

PubMed1992

On criteria for hearing impairment in children.

As objective criteria concerning hearing impairment/disability may be poorly related to the behavioral patterns of children with hearing deficits, the present investigation was performed. A consecutive series of 172 children, who were examined for the first time at the Audiological Department, was subdivided according to age into two groups: one comprising 98 children at an age from 49 to 84 months, the other comprising 74 children greater than 84 months of age. This second group is supposed to complain of hearing problems if present, and thus constitutes a reference group. Using the criterion for hearing impairment: BEHL 0.5-4 kHz greater than 20 dB HL, the data demonstrated that the frequency of correct and false positive suspicion (detection) of a hearing impairment is similar in parents and professionals with an observer sensitivity of 88%. In addition the frequency of suspicion in parents and professionals in relation to degree of hearing loss corresponds to the frequency of hearing problems, as experienced in the reference group of older children. A certain discrepancy exists between the applied criterion of BEHL 0.5-4 kHz greater than 20 dB and the hearing level resulting in deviating behavioral pattern or experienced hearing deficit in children. This may be ascribed to the predominantly conductive hearing loss in the examined sample. It is concluded that additional investigations on criteria for hearing impairment/disability, including also children with sensorineural hearing loss should be undertaken.

Adolescent↗

PubMed1992

Potential language and attentional networks revealed through factor analysis of rCBF data measured with SPECT.

We used changes in regional cerebral blood flow (rCBF) to disclose regions involved in central auditory and language processing in the normal brain. rCBF was quantified with a fast-rotating, single-photon emission computerized tomograph (SPECT) and inhalation of 133Xe. rCBF data were obtained simultaneously from parallel, transverse slices of the brain. The lower slice was positioned to include both Broca's and Wernicke's areas. The upper slice included regions generally regarded by neurobehaviorists as less related to primary auditory or linguistic functions. We presented three types of auditory stimuli to ten healthy, young volunteers: (a) diotically presented Danish speech, (b) dichotic word stimulation, and (c) white noise. Wilcoxon's signed ranks sum test revealed increased rCBF in language-related areas of cortex, viz., Wernicke's area and its right-sided homologous area as well as in Broca's area (left hemisphere), when subjects listened to narrative speech, compared to white noise (baseline). No significant rCBF differences were detected with this test during dichotic stimulation vs. white noise. A more sophisticated statistical method (factor analysis) disclosed patterns of functionally intercorrelated regions. The factor analysis reduced the highly intercorrelated rCBF measures from 28 regions of interest to a set of three independent factors. These factors accounted for 77% of the total variation in rCBF values. These three factors appeared to represent statistical analogues of independent brain networks involved in (I) auditory/linguistic, (II) attentional, and (III) visual imaging activity.

Acoustic Stimulation↗

PubMed1992

An audit of hearing aid quality in Denmark.

This investigation was aimed towards an evaluation of the quality of hearing aids, dispensed from a National Hearing Health Service. During a twelve month period all subjects attending the hearing aid servicing section were recorded, and the reason for the visit noted. A total of 4450 people attended (45% males, 55% females) with a median age of 71 years, range 8-99 years. Among these 60.4% of attendances could be ascribed to defective hearing aids. Among the defective hearing aids 20.6% had been used less than one year and 91.4% of the defective aids had been used less than four years, that is within the guarantee period. The recording demonstrated that specific series of aids have a defect rate of 6.6-70.9% within the first year of use. A comparison between the frequency of defects in different types of hearing aids (BTE, ITE, ITC and other hearing aids) was performed indicating that there is a risk of 8.6% that BTE will be defective within one year of provision. As 20.6% of the applicants' defective hearing aids had been used less than one year, it is concluded that the quality of hearing aids should be improved; the hearing aid manufacturers' main categories for fault finding can be used in the audiological departments within the National Hearing Health Service; the recording offers valuable data on the quality of hearing aids, and specifically poor series can be revealed within a limited period.

Adolescent↗

PubMed1991

Audiometric tests in gene carriers of Norrie's disease.

The purpose of the present study was to validate the reliability of audiometric testing procedures in the identification of carriers of Norrie's disease by using DNA analysis. Potential female carriers of Norrie's disease were investigated by means of Békésy tracing audiometry and stapedial reflex thresholds previously found to reveal carriers of recessively inherited hearing impairment by means of peculiar 'dips' and elevation in the thresholds. Relating the audiometric test results to the outcome of the DNA analysis the previous findings could not be confirmed. In addition no concordance between the two audiometric test procedures was demonstrated, and Békésy threshold tracing exhibited poor repeatability and sensitivity. It is concluded that none of these audiometric test procedures are feasible for detection of carriers of an X-linked hearing disorder, such as Norrie's disease.

Acoustic Impedance Tests↗

PubMed1991

Human temporal bone findings in acquired hypothyroidism.

Histological studies of the auditory organ in patients with acquired hypothyroidism are scarce. Thus the aim of the present study was to examine the temporal bones and the brain in subjects with hypothyroidism. Four temporal bones and two brains from clinically and biochemically hypothyroid subjects were removed and evaluated by light microscopy determine to the morphological changes and deposition of neutral and acid glycosaminoglycans. An audiogram from one of the patients showed a sensorineural hearing loss, which could be ascribed to occupational noise exposure. The study revealed histological changes compatible with age and infectious disease. No accumulation of neutral or acid glycosaminoglycans could be demonstrated in the temporal bones, or in the brains.

Adipose Tissue↗