摘要:

Objective:Long-term effects of otitis media (OM) on hearing in both conventional and high frequency (HF) regions in children were studied.Design:Children with OM were enrolled in a prospective study of sequelae after tympanostomy tube insertion (intubation) and were examined serially at 6-mo intervals with audiometry and multifrequency tympanometry, and every 3 mo with tympanometry and otoscopy for at least 3, and up to 5 yr. Hearing thresholds in conventional and HF regions were compared with those of an age-matched control group of children who had 2 or fewer documented episodes of any type of OM since birth. Frequency of OM during follow-up, number of intubations, use of ototopical eardrops, age, and sex along with several other factors were analyzed for a relationship to HF hearing loss.Results:Otitis media history was associated with poorer HF hearing, but the presence of subtle residual middle ear dysfunction was not associated with an additional effect on HF hearing. Active middle ear disease significantly affected both conventional and HF thresholds. The number of intubations and frequency of OM during follow-up were significantly and positively associated with poorer HF thresholds. Several other factors, including middle ear appearance at intubation, presence of tympanosclerosis, age, male gender, and use of ototopical eardrops, were also associated with poorer HF hearing but failed to reach significance after their intercorrelation with number of intubations and frequency of OM was considered.Conclusions:High frequency hearing loss was associated with OM after middle ear disease resolved and after middle ear dysfunction was excluded. Relatively poorer HF hearing thresholds found for older children with OM histories appeared to be attributable to time spent with ear disease. Children at greatest risk for HF hearing loss were those who required multiple intubations. Older children tended to have poorer hearing in both conventional and HF regions, suggesting that the effects of OM on hearing thresholds may be progressive.

ISSN:0196-0202    

出版商:OVID    

年代:1996

数据来源: OVID

摘要:

Objective:The objective of this investigation was to determine the effect of the aging process on various measures derived from multifrequency tympanograms.Design:Tympanograms were recorded at 226 Hz and at one-sixth octave intervals from 250 through 2000 Hz from 136 adult male subjects; 20 in each decade of life from age 20 through age 79 and 16 older than 79 yr of age. Analyses were performed on two measures of resonant frequency of the middle ear, two measures of static admittance at 226 Hz, and tympanometric width at 226 Hz.Results:No systematic effect of age on any of these measures was evident in this population except for a small, but significant, correlation between tympanometric width and age. Analyses of variance indicated no significant difference among mean values on any measure when subjects were grouped by decade of life. Values of these tympanometric variables are reported to add to the growing base of data from normal low-frequency and multifrequency tympanograms.Conclusions:The main finding of this investigation indicates that normative values of middle ear resonance, admittance, and tympanometric width obtained from groups of adults of various ages can be applied to elderly men.

ISSN:0196-0202    

出版商:OVID    

年代:1996

数据来源: OVID

摘要:

Objective:The purpose of the present study was to obtain the median values and distributions of tympanometric variables and the distributions of acoustic reflex thresholds for three age groups of unselected school-aged children. Furthermore, the investigation was undertaken to provide normative immittance data for selected, otologically normal 7-, 10-, and 14-yr-old children.Design:A total of 687 children, aged 6 to 15 yr, were thoroughly examined clinically, audiometrically, and tympanometrically. The same examinations were made in 471 otologically normal children, selected from the total population on the basis of the findings that both tympanic membranes were otomicroscopically healthy, and the hearing thresholds were better than or equal to 25 dB HL at all frequencies.Results:The results showed that the median equivalent ear canal volume(Vec) increased from 0.65 ml to 1.00 ml with increasing age both in the unselected and selected populations. The median peak admittance values(Ytm) were between 0.55 and 0.5 mmho in the respective study groups, somewhat higher in older than in younger children. The same tendency was also seen in gradient and tympanometric peak pressure (TPP) results. Depending on the age, the median tympanometric peak pressures were 5 to 10 daPa higher in otologically normal children than in the unselected population. The median TPP was -10 daPa in a group of unselected children, and -5 daPa in a group of otologically normal children. The distribution of ipsi- and contralateral acoustic reflex thresholds is presented. Thresholds were higher in younger than in older children.Conclusions:The obtained results give new information on immittance findings in an unselected sample of school-aged children who were representative of children in the general population. Furthermore, the results are useful as normative immittance values in 7-, 10-, and 14-yr-old children when the limitations relating to the equipment are taken into account.

ISSN:0196-0202    

出版商:OVID    

年代:1996

数据来源: OVID

摘要:

Objective:The overall objective of the present study was to assess the efficacy of FM system use in the home setting for a group of preschool children with mild-to-severe sensorineural hearing loss. Changes in language acquisition were monitored and compared with similar measures from a group of children who used hearing aids. Secondarily, the perceived benefits and practical problems associated with FM system use across a variety of nonacademic situations were documented.Design:Ten children with mild-to-severe sensorineural hearing loss participated in a 2-yr longitudinal study investigating the efficacy of FM system use in the home setting. The subjects were divided into two groups: one group was instructed to use FM systems at home as often as possible while the other used only their personal hearing aids. Changes in language acquisition were monitored in both groups. Subjective benefit and the practical problems associated with use of FM systems outside of traditional academic environments were monitored via daily use logs, a weekly observation inventory, and a situational listening profile.Results:The majority of children in both groups improved in all measures of language development over the study interval. Although there were relatively large individual differences in performance for some measures, no statistically significant differences between the FM and hearing aid users were found. However, some children in the FM group made unusually large gains in some aspects of language development over the study interval. In addition, both parents and children reported benefits of FM system use in specific listening situations. Throughout the 2-yr study, a number of practical problems associated with FM system use outside the classroom were identified.Conclusions:Formal language measures did not yield significant differences between the FM and HA groups, but some subjects had rates of language acquisition which suggested that FM system use may be beneficial in selected cases. In addition, subjective reports of FM system benefit suggest that appropriate use of the device may facilitate effective communication in a variety of listening situations. Although recent advances in FM system design may minimize some of the factors that reportedly restricted consistent FM use in this study, the complexities associated with the modes of operation and problems with FM interference remain issues that require consistent audiologic monitoring of FM system use in nonacademic environments.

ISSN:0196-0202    

出版商:OVID    

年代:1996

数据来源: OVID

摘要:

Objective:To assess the feasibility of obtaining transient-evoked otoacoustic emissions (TEOAEs) directly in the nursery, to examine the nature of failures in this population, and to determine the time requirements for this test relative to the auditory brain stem response (ABR).Design:TEOAEs and ABRs were recorded from 149 ears, at bedside, in the recovery or intensive care nursery. Subjects were selected according to the risk criteria developed by theJoint Committee on Infant Hearing(1991). Parametric and nonparametric statistical procedures were conducted to describe demographics and test results, to evaluate TEOAE measures by subgroups, and to compare infants by pass/fail outcome. Multivariate techniques were applied to the data to test implicit hypotheses regarding the source of TEOAE failures. In addition, the time required to carry out each test was evaluated in an analysis of variance design.Results:63.5% of the ears studied passed both procedures, 5% failed both, and 31.5% passed the ABR but failed the TEOAE. Although infants who failed the TEOAE had lower birthweights, shorter gestational periods, and were younger at the time of testing, no statistical differences were found for nursery(intensive care nursery/recovery), bed type (isolette/open crib), ear(left/right), or gender. Infants <38 wk postconceptional age had smaller TEOAE responses and lower noise levels than did those >37 wk. There were no differences in environmental noise levels (at the microphone) for passed or failed ears or whether infants were in isolettes or open cribs. Statistically prolonged ABR wave I latencies (Z-scores) at 60 and 30 dB among infants who passed the ABR but failed the TEOAE indicated some obstruction to the acoustic stimulus, whereas TEOAE noise measures neither distinguished these groups nor identified this condition.Three summary times involved in the performance of these tests were obtained: (a) actual test time, measured from start to completion of data collection with a stopwatch; (b) total test time, defined by the actual test time plus the respective preparation, setup, and cleanup (ABR) time; and (c) time reported by the computer system during intrinsic sampling. There were no significant differences in actual or total test times, but these values were distinguished from the machine time, which represented an underestimate of the time required to effectively conduct each test.Conclusions:These findings show that TEOAEs can be acquired in the nursery, but the high false-positive rate suggests that alternative or additional screening methods, for example, the ABR, must also be available. It must be recognized that TEOAE failures increase test time, thereby negating any savings relative to ABR screening alone.

ISSN:0196-0202    

出版商:OVID    

年代:1996

数据来源: OVID

摘要:

Since lidocaine is used to relieve the symptoms of Meniere's disease and tinnitus, its effects on the human cochlea is of specific interest. In experimental animals, topically administered lidocaine affects cochlear electrophysiology in a specific, dose-dependent manner. In the current study, lidocaine (40 mg in 1 ml of saline) was delivered intratympanically in six patients with essentially normal hearing in an attempt to alleviate tinnitus. Auditory function was assessed by pure tone audiometry, auditory evoked brain stem responses (ABR), and transiently evoked otoacoustic emissions (TEOAE) to observe possible drug effect in the auditory system. In five patients, saline was injected prior to lidocaine for control purposes. Saline injection did not create significant changes in any of the measures. After a 2 hr follow-up period, intratympanic injection of lidocaine caused a 2 to 10 dB reduction in TEOAE level at 1 to 3 kHz frequencies. This reduction was at its maximum at the 30 min post-injection sampling point, and was followed by a slow recovery. At 2 hr post-injection, TEOAE amplitude was still 2 to 4 dB below baseline level. Pure tone thresholds were slightly affected 30 min after intratympanic lidocaine injection, but were fully recovered 1 hr after the injection. Lidocaine injection did not cause any changes in ABR latencies or amplitudes in any of the patients. These results suggest that the dose of intratympanically administered lidocaine used here has a specific effect on the organ of Corti structures in human subjects, without significantly affecting the auditory nerve or central auditory pathways. The relationship of the drug effect in conjunction with a possible effect on inner ear disorder might help to localize the site of disorder.

ISSN:0196-0202    

出版商:OVID    

年代:1996

数据来源: OVID

摘要:

Objective:This study was designed to seek a nationwide perspective on the status of identification and intervention for infants and young children with hearing loss.Design:Three hundred thirty-one parents, whose children ranged from infancy to 5 yr of age, returned a mail survey that included respondents from 35 states. Parents were asked to report the approximate age of suspicion, diagnosis, hearing aid fitting, and initiation of early intervention services. Demographic information, risk factors, if known, and reasons for delay were also investigated.Results:Results revealed substantial delays between parental suspicion, audiologic-medical diagnosis, fitting of acoustic amplification, and initiation of early intervention services; however, the pattern of delay was different for children with known risk factors than it was for those without known risk factors. The median age of identification and intervention was lower than that reported by some previous investigators, although a considerable range was reported for each category.Conclusions:The median age of identification and intervention, although still higher than optimal, may be improving. Further research is needed to identify the many factors that continue to delay the timely management of hearing loss in young children.

ISSN:0196-0202    

出版商:OVID    

年代:1996

数据来源: OVID

摘要:

Objective:The aim of this study was to investigate the influence of pigmentation on the reduction in temporary noise-induced threshold shift (TTS) due to low level acoustic stimulation (LLAS). A pigmentation-dependent LLAS effect on TTS could be interpreted as a strial melanocyte involvement in LLAS. It could not be explained by cochlear sensorineural structure changes only.Design:Teenagers were classified according to eye color (n= 6 + 6) and exposed to music at 70 dBA 6 h per day for 9 days (LLAS). TTS was measured before, during, and after the LLAS period.Results:It was shown that LLAS reduced TTS significantly more in blue-eyed than in brown-eyed subjects. The difference in TTS remained for at least 1 wk after the cessation of LLAS.Conclusions:It is suggested that the observed difference in LLAS effect is due to strial melanocyte differences in free radical defense. It is also possible that other cochlear antioxidant enzyme systems, responsible for inactivation of harmful oxygen radicals and simultaneously involved in melanin synthesis such as the thioredoxin reductase/thioredoxin electron transfer system are activated.

ISSN:0196-0202    

出版商:OVID    

年代:1996

数据来源: OVID

摘要:

Objective:A new speech processing concept and its implementation cochlear implant neural net, simulation and stimulation (CINSTIM), for cochlear implant systems is currently under investigation. The main objectives of this new strategy are to improve speech perception within the early rehabilitation period for prelingually deaf cochlear implant users and to improve speech perception in noise for all implant users. The advantage of this approach is the capability to assess and compare entirely different speech processing methods within the existing implant hardware.Design:The processing concept is based on discrete sequences of distinguishable stimulus patterns, robust speech processing, and a classifier. The embedded Kohonen classifier employs unsupervised neural net algorithms.Results:Initial experimental results have validated the general processing scheme as well as the development of this complex software. In addition, a limited alphabet of distinguishable stimulus patterns was achieved and assessed with experienced users of a conventional cochlear implant system. Test subjects were able to learn and recognize up to 60% of these artificial patterns after a few training sessions. Currently this speech processing strategy is being evaluated through the Cochlear MSP system; however, it is compatible with the other computer driven digital cochlear implant systems.

ISSN:0196-0202    

出版商:OVID    

年代:1996

数据来源: OVID

ISSN:0196-0202    

出版商:OVID    

年代:1996

数据来源: OVID