Hearing impairment among adults--extent of the problem and scientific evidence on the outcome of hearing aid rehabilitation.

Scientific surveys on current and estimated prevalence of hearing impairment (HI) in adult populations (> or = 18 years of age) in Denmark, Finland, Norway, Sweden and the United Kingdom, and scientific reports on the outcome of hearing aid (HA) rehabilitation worldwide were reviewed. Only a few of the studies meet strict scientific criteria, and many locally clinically relevant studies cannot be generalized to larger populations. Population-based studies indicate an increase in prevalence of HI with age, but because of differences in study populations and available national population statistics, the studies do not allow reliable comparisons between countries or estimation of future prevalence of HI. Studies on HA prescription or outcomes do not provide uniform data in favour of non-linear amplification, but they do show some subject preference for the newer technology. No conclusions can be drawn regarding the degree of HI and the effects of amplification. The literature review alone gives only limited information regarding the extent of the problem of HI in adult populations in the target countries. Similarly, only a few studies on HA outcome meet strict scientific criteria and even fewer studies correlate rehabilitation outcome with the degree of HI, disability or handicap.

Speech perception and functional benefit after cochlear implantation: a multicentre survey in Finland.

This study was done to survey the effect of cochlear implantation on hearing level, speech perception and listening performance in Finnish-speaking adults. The subjects of the study comprise 67 adults. Pure-tone thresholds (0.125-8 kHz), word recognition and listening performance were studied before and after implantation. After switch-on of the implant, the median values of PTA(0.5-4 kHz) in the sound field were fairly stable across the evaluation period. Three months after switch-on of the implant, the mean word recognition score was 54%. There was clear improvement in the mean word recognition scores over a longer period of time, the mean score being 71% 24 months after switch-on. Six months after switch-on, the majority of subjects (40/48) were able to recognize some speech without speechreading, and 26 of these 48 subjects were able to use the telephone with a known speaker, gaining good functional benefit from the implantation.

Long-term outcome of early childhood hearing impairments in northern Finland.

Early childhood hearing impairment (HI) may have a marked negative effect on educational outcome and employment status in adulthood. The late outcome of 51 Finnish mildly to profoundly HId children born in the period 1965-1979 was studied using a questionnaire posted to the subjects. Subjects included in the study had an early childhood sensorineural, non-syndromal hearing impairment with no known associated handicaps. The response rate to the inquiry was as high as 88% (45/51). The subjects had qualified educationally at a somewhat lower level than their age peers according to nationwide statistics; 48% of the respondents belonging to the labour force were currently unemployed (versus 15% of all the 25-to 29-year-olds in Finland in 1997), but their employment status was not associated with the HI grade. In particular, the severely and profoundly HId often had needed special support from the employment authorities to find work.

On the construction of a Finnish audiometric sentence test.

To respond to the demands of clinical practice and the needs of rehabilitation, a Finnish audiometric sentence test is being developed. The test consists of 10 sets of 10 sentences, each set serving as an independent test. The test is scored by words (50 per set). Homogeneity between the sets was guaranteed by a number of linguistic and phonetic criteria, controlled by using the Virko Sentence Analyzer, a programme especially constructed for the purpose. Recognition tests for the validation of the sentence sets were made with young normally hearing adults (n = 70; age group 18-25 years). Psychometric recognition properties of the test are described. The selection process of the final 10 sentence sets is illustrated.

Speech perception and functional benefit after multichannel cochlear implantation.

This study was done to investigate the effect of a multichannel cochlear implant on speech perception and the functional benefit of cochlear implantation in Finnish-speaking postlingually deafened adults. Fourteen subjects were enrolled. Sentence and word recognition were studied with open-set tests auditorily only. One year after implantation, the listening performance was assessed by case histories and interviews. Before implantation for subjects with a hearing aid, the mean recognition score was 38% for sentences and 17% for words. One year after switching on the implant, the mean recognition score was 84% for sentences and 70% for words. Before implantation, the majority of the subjects were not aware of environmental sounds and only a few were able to recognize some environmental sounds. One year after switching on the implant, the majority of the subjects were able to use the telephone with a familiar speaker. All the subjects were able to recognize speech auditorily only and had thus gained good functional benefit from the implant.

Cochlear implant patients and quality of life.

During the last two decades, cochlear implants have been available for profoundly hearing-impaired patients who do not benefit from conventional hearing aids. The quality of life of these implantees has not been extensively studied, and has not been studied at all in Finland. To assess their quality of life, the Nottingham Health Profile questionnaire was sent to all adult implanted patients in Finland. Implantees tended to have more favourable average pain, emotional reaction and mobility indexes in each age group studied than the average population. Social-isolation seemed to be more common in the youngest and oldest age groups of implantees. Apparently, implantees are physically healthier than the average population. However, a bias caused by the strict selection of implant candidates cannot be excluded.

The effect of a multichannel cochlear implant on phoneme perception.

This study was done to investigate the effects of a multichannel cochlear implant on phoneme perception in Finnish-speaking postlingually deafened adults. Phoneme recognition was studied with 100 prerecorded nonsense syllables (open-set) presented at 70 dB SPL, auditorily only, in a free-field situation. Ten subjects were tested before implantation both with and without a hearing aid (HA), and 3, 6 and 12 months after switching on the implant. Before implantation without a HA, the subjects did not recognize vowels, consonants or syllables. Four of the subjects used a HA before implantation, and the mean recognition scores of these subjects were 34% for vowels, 28% for consonants and 13% for syllables. One year after switching on the implant, the mean recognition scores were 77% for vowels, 66% for consonants and 46% for syllables. According to phonological analysis vowels appear to be easier to perceive than consonants during the first stage after multichannel cochlear implantation.

Cochllear implants and GSM phone.

Use of a telephone and GSM phones, in particular, was assessed by means of a postal interview sent to all adult Finnish implantees. The response rate was very high (87%). Fifty-one of the 61 respondents used a telephone and 27/61 also used a mobile phone, usually a digital phone. Two GSM phone models from Nokia (3110 and 6110) were tested with three different cochlear implant systems used by nine patients. Definite differences between the processors were found. Nucleus Spectra (two implantees) could not be used with any of the GSM phones under any test condition. Nucleus SPrint was incompatible with both GSM phone models in a poor field, while GSM phone model 6110 could be used in a good field. The Med-El Combi 40+ processor was compatible with both GSM models tested under any condition.

Speech perception after multichannel cochlear implantation in Finnish-speaking postlingually deafened adults.

This study was done to examine the short-term and long-term effects of multichannel cochlear implantation on speech perception in Finnish-speaking adults. The subjects comprise 20 adults. Pure-tone thresholds (0.125-8kHz), discrimination of phoneme quantity, sentence recognition, word recognition, phoneme recognition and listening performance were studied before and after implantation. After switch-on of the implant, the median pure-tone threshold values in the sound field were comparable to the level of mild hearing impairment. Most improvement in sentence recognition took place during the 6 months after the switch-on (mean score 74%). In word recognition, most improvement took place during the 12 months after the switch-on (mean score 66%), and clear improvement was noted even thereafter. In phoneme recognition, the performance of the subjects improved over the entire follow-up period, and 24 months after the switch-on the mean score was 52%. Individual variation was seen in the performance of the subjects. With 3 months of listening experience, all subjects were able to recognize some speech without speechreading, and they gained good functional benefit from the implant. The use of speech recognition tests with different degrees of difficulty is essential for the follow-up of adult cochlear implant subjects.

Aetiology and risk indicators of hearing impairments in a one-year birth cohort for 1985-86 in northern Finland.

The aetiology and risk indicators of hearing impairments of all types and degrees were studied in a 1-year birth cohort of 8713 children from northern Finland. The subjects (7 years of age) included in the clinical and audiometric examinations were recruited by standard clinical criteria, i.e. suspicion of parents according to a questionnaire, abnormal hearing screening result or a hearing impairment noted in hospital records (n = 541), and by random sampling from among the 8172 not suspected (n = 1009). One-hundred-and-one subjects in the group suspected of having hearing impairment and 27 subjects in the random sample eventually had hearing impairment. The aetiology could be defined in only 44.5% of the cases, ear infections being the most common. In this relatively small series, only a few risk indicators (congenital anomalies, meningitis and a history of ear discharge lasting for over 1 month) could be shown to be associated with impaired hearing in a logistic regression analysis.

Epidemiology of moderate to profound childhood hearing impairments in northern Finland. Any changes in ten years?

The epidemiology of childhood hearing impairments was studied in a clinical series of the birth cohorts for 1973-82 and 1983-92 from a geographically well-defined area. The overall prevalence of hearing impairments with PTA0.5-4 kHz > or = 40 dB was 1.2/1000 live births. Even in the later cohort, the median age ascertainment was 2.6 years for the congenital or early acquired group and 3.0 years for all impairments. Risk indicators for hearing impairment were present in half of the children, and those referred for the risk were ascertained at the median age of 1.1 years. The delay from suspicion to ascertainment was over a year in about one fifth of cases, while the median time from referral to ascertainment was only 1.8 months. The planning and implementation of neonatal hearing screening are suggested, and general information is given on paedoaudiology for both parents and professionals. A database could be beneficial in increasing the systemacy of the diagnostic process.

Effect of hearing impairment on educational outcomes and employment up to the age of 25 years in northern Finland.

The association between hearing impairment in adolescence and school performance and the outcome of education was studied among 25-year-old subjects followed since pregnancy in the Northern Finland birth cohort. The series, 395 subjects with abnormal hearing and 977 randomly selected controls, was based on a questionnaire on hearing and school achievement sent to 11780 members of the cohort alive at the age of 14 years, and on audiometric screening test requested from health centers. Hearing loss was defined as 'clinically significant' if the pure tone average (PTA; mean of the thresholds at 0.5, 1 and 2 kHz) exceeded 25 dB in the better ear; a threshold of > or = 30 dB at 4 kHz and a PTA of < or = 25 dB as '4 kHz loss'; and as 'slightly abnormal' if any of the thresholds exceeded 20 dB at any frequency and the case did not belong to the above two categories. The more severe the hearing impairment, the poorer was the child's performance at elementary school. Those with normal hearing and those with a slightly abnormal or 4 kHz loss were equally often accepted for intermediate education (88%), while those with a clinically significant loss had the lowest acceptance figures (64%). When adjusting for neurological and social confounders, excluding mental disability, the risk of not qualifying from intermediate or higher education at all was twice as high among those with a clinically significant loss as among the controls (OR 2.1, 95% CI 1.13-3.8), and was still elevated after adjustment had been made for all the relevant perinatal, neurological and social factors (OR 1.9, 95% CI 1.02-3.6). 14% of those with a clinically significant hearing loss, 9% of the subjects with a 4 kHz loss and 7% of those with normal hearing were unemployed at the age of 25 years. Hearing impairment appears to have effects on both the outcome of education and employment status.

Clarithromycin vs. amoxicillin suspensions in the treatment of pediatric patients with acute otitis media.

Clarithromycin is a new macrolide antibiotic that is active in vitro against a variety of organisms that are responsible for acute otitis media in children. The parent compound is metabolized to microbiologically active 14-hydroxy clarithromycin, which is especially active against Haemophilus influenzae. The safety and efficacy of clarithromycin and amoxicillin suspensions were compared in the treatment of acute otitis media in children 1 to 12 years of age inclusive. This was a Phase III, single blind (investigator-blind), randomized, multicenter clinical trial. Clarithromycin oral suspension was given in a dose of 7.5 mg/kg (maximum, 500 mg) twice daily, and amoxicillin suspension in a dose of 20 mg/kg (maximum, 750 mg) was given twice daily for 7 to 10 days in a 1:1 ratio. Clinical evaluations were performed pretreatment, within 48 hours posttreatment and 10 to 14 days posttreatment. Myringotomy was performed in every child to obtain a microbiologic sample pretreatment and at subsequent visits as clinically indicated. A total of 79 children were enrolled, 39 in the clarithromycin and 40 in the amoxicillin treatment group. Thirty-two children were excluded from the efficacy analysis for various reasons. Clinical success (cure and improvement) rates at 0 to 4 days posttreatment were 93% for clarithromycin and 90% for amoxicillin (P > 0.999). Altogether 17 children (10 receiving clarithromycin, 7 receiving amoxicillin) experienced some adverse event, with gastrointestinal disorders being the most common complaint. No clinically significant differences in laboratory tests were found between the groups.(ABSTRACT TRUNCATED AT 250 WORDS)