摘要:

Objective:Population ascertainment of children having bilateral moderate to profound hearing impairment was undertaken to find out how many had passed (false negatives) and how many had failed (true negatives) a neonatal screening test based on transient-evoked otoacoustic emissions (TEOAE).Design:Neonatal screening using a purpose-built TEOAE instrument was undertaken in neonates, at eight hospitals in districts distributed around the United Kingdom starting in 1988. Screening was targeted on neonates at risk of hearing impairment. A total of 7500 babies had been tested by the end of 1995. Searching of audiological records in the districts completed at the end of 1995 ascertained 218 children born between January 1988 and December 1993 who had hearing threshold levels in both ears of 50 dB or more, averaged over the speech frequencies 0.5, 1, 2, and 4 kHz. Of those, 47 had completed the neonatal TEOAE screening test. Retrospective examination of their TEOAE records indicated whether they had passed or failed the screening test.Results:Eleven of the 47 had passed the screening test, although two of those had documented acquired hearing impairment occurring after screening. Disregarding those two cases leaves nine false negatives out of 45, giving a sensitivity estimate of 80% (36 divided by 45). In two of the nine cases, there was documented evidence of progression, one of whom had a family history of progressive hearing loss.Conclusions:Targeted neonatal hearing screening programs based on TEOAE can expect to identify hearing impairment in approximately 80% of babies screened. The cause of false negatives is a matter for conjecture. There may be several reasons: the test may give an incorrect result, there may be a later acquired hearing impairment, or there may be a progressive hearing loss of unknown origin. Passing a neonatal screening test is not a valid reason to forego further surveillance, or to disregard parental suspicion of hearing impairment.

ISSN:0196-0202    

出版商:OVID    

年代:1997

数据来源: OVID

摘要:

Objective:To increase the speed of a distortion product otoacoustic emissions (DPOE) test of cochlear function by employing a new multiple-tone-pair method and to validate the method.Design:We used a new method of employing multiple tone pairs in measuring DPOEs proposed by Zurek and Rabinowitz and implemented in a modified Grason-Stadler Model GSI-60. We investigated the applicability of the multiple-pair method by comparing the 2f1-f2DPOEs obtained with a 3-pair method with the conventional 1-pair results in human adults; f1and f2represent two frequencies of each tone pair, f1< f2, f2/f1= 1.2. We used two sets of 3-pair stimuli: 1) f2at 1.5, 3, and 6 kHz; and 2) f2at 2, 4, and 8 kHz. The 1-pair stimuli had f2at each of the above six frequencies. The primary tone levels were L1= 65 and L2= 50 dB SPL re 20 µPa.Results:We obtained DPOEs from 98 ears with normal hearing and 94 ears with sensorineural hearing loss in 103 human adults. We found: 1) that the DPOE levels obtained with the 3-pair method were strongly correlated with those of the 1-pair method, with correlation coefficients of 0.83 to 0.96; 2) that the mean DPOE level versus frequency functions for the normal ears were similar between the 3-pair and 1-pair methods; a 2-way analysis of variance indicated no significant difference between the two methods; 3) that the mean difference between DPOE levels obtained with the 3-pair and 1-pair methods was small (less than 1.3 dB in 11 of the 12 conditions examined, i.e., six frequencies each for normal ears and hearing-impaired ears) although the differences were significant in 6 of the 12 conditions as determined by the pairedt-test; and 4) that the DPOE test performances of distinguishing normal from impaired ears were similar between the 3-pair and 1-pair tests; areas under the receiver operating characteristic curves were not significantly different between the two tests for four of the six frequencies tested as determined by a statistical procedure of Hanley and McNeil; for the remaining two frequencies where the differences were significant, each of the two tests was better than the other at one frequency.Conclusions:The 3-pair DPOE method yielded results generally in good agreement with those of the conventional 1-pair DPOE method. To our knowledge, this is the first systematic study of a multiple-pair DPOE method. Because a 3-pair method can be conducted approximately two to three times as fast as a 1-pair method, the former is advantageous, particularly for an auditory screening test.

ISSN:0196-0202    

出版商:OVID    

年代:1997

数据来源: OVID

摘要:

Objective:The purposes of this study were: To determine the quantitative and qualitative changes that occur in transient-evoked otoacoustic emissions(TEOAEs) in older individuals without addressing the effect of aging alone and without correction for hearing loss of the subject selection. To investigate the clinical value of measuring TEOAEs in the routine audiological evaluation of older people reasoning that a finding of hearing loss in the presence of TEOAEs could indicate a form of presbycusis with a primary central component.Design:Click-evoked otoacoustic emissions (CEOAEs) were measured in 201 subjects without middle ear problems aged 60 yr and older (range 60 to 97 yr) who volunteered for the study because of complaints concerning their hearing. Audiological procedures included a pure-tone audiogram, modified Speech Perception in Noise test (German version: Basler Satztest), and the Hearing Handicap Inventory for the Elderly (German version). Results from ears with a pure-tone average (PTA) at 0.5, 1, and 2 kHz of ≤30 dB HL were further analyzed with respect to the presence or absence of CEOAEs. In addition, tone burst evoked otoacoustic emissions (TbOAEs) were tested in ears with responses to click stimuli. The test consisted of a paradigm used previously in our laboratory to assess superposition and suppression of frequency within the cochlea (seeXu, Probst, Harris, & Roede, 1994).Results:CEOAEs were not detectable in ears with a PTA >30 dB HL. The prevalence of CEOAEs in ears with a PTA ≤30 dB HL was 60%. Response levels decreased as hearing thresholds became poorer, but there was no apparent influence on TEOAE level due to age alone. The audiological measures from ears with and without CEOAEs and with PTAs ≤30 dB HL were similar with the exception of small between group differences at lower frequencies. The TbOAE results showed no differences in linear superposition and suppression when results were compared with those of younger subjects tested previously.Conclusions:The lower overall amplitudes of TEOAEs and the lower prevalence of 60% in comparison to results from younger subjects with normal hearing imply that cochlear changes do occur with aging. However, the preservation or loss of TEOAEs does not separate subjects with presbycusis into distinct audiological categories or handicaps. Tone burst results suggest that frequency processing within the cochlea is not affected by age alone. We conclude that TEOAEs add no relevant information in the routine clinical evaluation of elderly persons with hearing problems.

ISSN:0196-0202    

出版商:OVID    

年代:1997

数据来源: OVID

摘要:

Objective:The purpose of this study was to compare listeners' subjective judgments of speech clarity via paired comparisons and category rating using stimulus conditions that varied in the relative spacing between stimulus items, producing either a wide or narrow range of performance.Design:Subjective judgments of speech clarity were measured via paired comparisons and category rating in 12 normal-hearing (Experiment 1) and eight hearing-impaired adults (Experiment 2). Sentences processed by six band-pass filters that increased monotonically in Articulation Index (AI) estimates constituted the stimuli to be judged. Using subsets of three filters from the group of six, subjective judgments were additionally obtained for stimulus conditions in which the performance ranges were wide (large differences in AI) and narrow (small differences in AI).Results:Speech clarity judgments obtained by paired comparisons and category rating were highly related to the AI estimates both for normal-hearing and hearing-impaired subjects. When the performance range was wide, both methods provided similar judgments for the normal-hearing subjects. For the hearing-impaired subjects, paired comparisons were more sensitive than category rating. When the performance range was narrow, paired comparisons were more sensitive than category rating in differentiating between filters for both groups of subjects. This difference was less obvious for the normal-hearing subjects when paired comparison data were converted to a scale comparable to the category ratings. Large between-subject variability was evident for the hearing-impaired subjects on the psychophysical scaling procedures, most notably for category rating.Conclusions:When judging the clarity among stimulus items where performance varied over a wide range, both category rating and paired comparisons provided comparable judgments for normal-hearing listeners. For conditions in which perceptual differences between stimulus items were restricted either by the choice of conditions or by the effects of sensorineural hearing loss, the method of paired comparisons was the more sensitive procedure.

ISSN:0196-0202    

出版商:OVID    

年代:1997

数据来源: OVID

摘要:

Objective:To examine changes in perceived vowel production accuracy over time in prelingually deafened children who use a multichannel cochlear implant(Nucleus 22 channel) or a multichannel tactile aid (Tactaid 7) and to compare the levels of perceived vowel production accuracy attained by the two device groups.Design:The subjects were participants in longitudinal studies of the effects of sensory aids on the development of perceptual, speech, and language skills. As part of these studies, imitative vowel productions were elicited and transcribed before each child received their sensory aid and at 6 mo intervals thereafter. Data for the current study was obtained from the predevice interval and a later interval (postdevice) that was an average of 1.8 yr after the subjects received their respective devices. The subjects' vowel productions were judged for accuracy in matching an imitative model and for correctness of vowel features (height and place). Within-group analyses were completed to determine if vowel production scores improved over the course of the study for each device group. Between group comparisons were performed to examine differences in mean scores at each interval.Results:Before receiving their multichannel devices, the two groups of subjects demonstrated similar imitative vowel production skills. After an average of 1.8 yr of device use, the cochlear implant subjects demonstrated significantly improved production of diphthongs and all vowel categories except low vowels. The Tactaid 7 subjects demonstrated significant improvement only in the production of diphtongs. Thus, cochlear implant recipients' vowel production skills were found to be significantly better than those of the Tactaid 7 users after a comparable amount of device experience.Conclusions:The vowel production gains of the cochlear implant subjects were similar in amount to those noted in other studies of children who use the Nucleus multichannel cochlear implant and further confirm the potential of this device for improved speech production in prelingually deafened children. The differences between the performance of the two groups demonstrate that vowel production skills improved to a greater degree through use of a multichannel cochlear implant than through use of the Tactaid 7.

ISSN:0196-0202    

出版商:OVID    

年代:1997

数据来源: OVID

摘要:

Objective:To assess the accuracy with which cochlear implant patients are able to match two stimuli on the basis of pulse rate pitch.Design:Patients were required to adjust the pulse rate of a comparison stimulus to match that of a fixed reference stimulus. The comparison and the reference stimuli differed in loudness or were presented to different electrodes.Results:Patients were able to match stimuli on the basis of pulse rate, with varying degrees of accuracy. Deviations from the target and the amount of variability were greater when stimuli were presented to different electrodes. The results also provide evidence regarding level-dependent pitch shifts.Conclusions:Because of methodological limitations, conclusions regarding pitch equivalence are limited. However, patients vary significantly in their ability to utilize temporal information.

ISSN:0196-0202    

出版商:OVID    

年代:1997

数据来源: OVID

摘要:

Objectives:The primary goal of this study was to evaluate alternative tympanometric parameters for distinguishing normal middle ears from ears with otosclerosis. A secondary goal was to provide guidelines and normative data for interpreting multifrequency tympanometry obtained using the Virtual 310 immittance system.Design:Nine tympanometric measures were examined in 68 normal ears and 14 ears with surgically confirmed otosclerosis. No subjects in either group had a history of head trauma or otoscopic evidence of eardrum abnormalities. Two parameters, static admittance and tympanometric width, were derived from standard low-frequency tympanometry and two parameters, resonant frequency and frequency corresponding to admittance phase angle of 45° (F45°), were derived from multifrequency tympanometry.Results:Differences between normal and otosclerotic ears were statistically significant only for resonant frequency and F45°. Group differences in resonant frequency were larger when estimated using positive tail, rather than negative tail, compensation. Group differences in both resonant frequency and F45° were larger when estimated from sweep frequency (SF), rather than sweep pressure, tympanograms. Test performance analysis and patterns of individual test performance point to two independent signs of otosclerosis in the patient group; 1) an increase in the stiffness of the middle ear, best indexed by F45° derived from SF recordings, and 2) a change in the dynamic response of the tympanic membrane/middle ear system to changes in ear canal pressure, best indexed by tympanometric width. Most patients were correctly identified by only one of these two signs. Thus, optimal test performance was achieved by combining F45° derived from SF recordings and tympanometric width.Conclusions:The findings confirm the advantage of multifrequency tympanometry over standard low-frequency tympanometry in differentiating otosclerotic and normal ears. Recommendations for interpreting resonant frequency and F45° measures obtained using the Virtual Immittance system are also provided. In addition, the relationship among different tympanometric measures suggests a general strategy for combining tympanometric measures to improve the identification of otosclerosis.

ISSN:0196-0202    

出版商:OVID    

年代:1997

数据来源: OVID

摘要:

Objective:To measure the field-to-microphone transfer function for two sizes of completely-in-the-canal (CIC) devices, at two loudspeaker azimuths.Design:Field-to-microphone transfer functions were measured for both standard- and micro-CIC instruments, at 0° and 45° azimuth, in a sample of 24 adults. This was accomplished with custom instruments, which allowed for a direct connection between the CIC microphone electrical output and the measurement/analysis instrumentation system.Results:For the standard-CIC, the peak in the average field-to-microphone transfer function was 8 dB at 4000 Hz for 0° azimuth and 13.7 dB at 5000 Hz for 45° azimuth.Conclusions:The results demonstrate and define, at two signal azimuths, the acoustic advantage of the CIC microphone placement relative to that reported for alternative hearing aid styles.

ISSN:0196-0202    

出版商:OVID    

年代:1997

数据来源: OVID

摘要:

Objective:The paper aims to show how insertion gain responses can be translated into equivalent headphone responses, and vice versa.Design:The relationship between the response types is theoretically derived by allowing for real ear to coupler differences and for real ear unaided responses.Results:The necessary corrections for each of these factors are obtained from published data, and the combined correction factors are compared with independently obtained published data.Conclusions:The equations and data presented can be used to translate insertion gain responses into responses suitable for use with equipment using headphones and, by inference, insert phones.

ISSN:0196-0202    

出版商:OVID    

年代:1997

数据来源: OVID

ISSN:0196-0202    

出版商:OVID    

年代:1997

数据来源: OVID