High-frequency (1000 Hz) tympanometry in normal neonates

The characteristics of high frequency (1000 Hz) acoustic admittance results obtained from normal neonates were described in this study. Participants were 170 healthy neonates (96 boys and 74 girls) aged between 1 and 6 days (mean = 3.26 days, SD = 0.92). Transient evoked otoacoustic emissions (TEOAEs), and 226 Hz and 1000 Hz probe tone tympanograms were obtained from the participants using a Madsen Capella OAE/middle ear analyser. The results showed that of the 170 neonates, 34 were not successfully tested in both ears, 14 failed the TEOAE screen in one or both ears, and 122 (70 boys, 52 girls) passed the TEOAE screen in both ears and also maintained an acceptable probe seal during tympanometry. The 1000 Hz tympanometric data for the 122 neonates (244 ears) showed a single-peaked tympanogram in 225 ears (92.2%), a flat-sloping tympanogram in 14 ears (5.7%), a double-peaked tympanogram in 3 ears (1.2%) and other unusual shapes in 2 ears (0.8%). There was a significant ear effect, with right ears showing significantly higher mean peak compensated static admittance and tympanometric width, but lower mean acoustic admittance at +200 daPa and gradient than left ears. No significant gender effects or its interaction with ear were found. The normative tympanometric data derived from this cohort may serve as a guide for detecting middle ear dysfunction in neonates.     

听力正常新生儿1000Hz声导抗分析

目的 分析通过耳声发射(OAE)听力筛查正常新生儿1000 Hz声导抗测试的特点,为新生儿听力筛查及新生儿中耳功能的评估提供参考依据.方法 采用GSI-70型自动耳声发射听力筛查仪对新生儿进行听力筛查,将双耳通过OAE听力筛查的正常新生儿按照纳入标准选为研究对象,共650例(1300耳),然后采用GSI TympStar VersionⅡ中耳分析仪对该研究对象进行中耳功能测试,收集探测音为1000 Hz的鼓室导抗图及其相关指标,对图形进行分型并计算各指标的95％医学参考值范围.结果 将纳入的1300耳的鼓室导抗图分类,其中1Y1B1G型732耳(占56.3％)、1Y3B1G型145耳(占11.2％)、0Y0B0G型269耳(占20.7％)、其他154耳(占11.8％).其中声导纳图Y中单峰型有967耳,计算单峰型声导纳图Y各指标的95％医学参考值范围,其中鼓室图峰压(tympanometric peak pressure,Tpp)为- 55.0～180.0 daPa、峰补偿静态声导纳值(peak compensated static acoustic admittance,Peak Ytm)为0.03 ～1.18 mmHo、鼓室图宽度(tympanometric width,TW)为70.0～230.0 daPa.结论 通过OAE听力筛查的正常新生儿1000 Hz探测音的声导纳图Y以单峰型为主.1000 Hz探测音的单峰型声导纳图Y的Tpp、Peak Ytm、TW的95％医学参考值范围可作为新生儿听力筛查及新生儿中耳功能评估时的参考依据.     

短声作为刺激声同侧声发射阈测定之临床价值

OBJECTIVE: To define that click can substitute for pure tone as a stimulus to measure ipsilateral acoustic reflex thresholds, and to find out the effect of probe frequency on acoustic reflex thresholds. METHOD: Using middle ear analyzer (GSI 33, version 2), we measured 23 normal voluntary participants (46 ears) for getting the pure-tone generated ipsilateral acoustic reflex thresholds at different probe frequency and the click evoked ipsilateral acoustic reflex thresholds at click rate 100/s and 180/s for every ear. RESULT: For pure tone, the ipsilateral acoustic reflex thresholds at 500 Hz, 1000 Hz, 2000 Hz, were (84.35 +/- 6.96) dB, (84.65 +/- 5.93) dB, (87.96 +/- 6.36) dB by using 226 Hz probe; (93.13 +/- 6.54) dB, (92.70 +/- 6.33) dB, (93.35 +/- 5.99) dB by using 678 Hz probe; (86.52 +/- 4.72) dB, (87.48 +/- 5.00) dB, (88.30 +/- 6.16) dB by using 1000 Hz probe. For click, the ipsilateral acoustic reflex thresholds at click rate 100/s and 180/s were (89.78 +/- 6.83) dB, (92.07 +/- 7.42) dB by using 226 Hz probe; (90.44 +/- 6.76) dB, (90.65 +/- 6.38) dB by using 678 Hz probe; (88.04 +/- 6.87) dB, (88.69 +/- 7.42) dB by using 1000 Hz probe. The acoustic reflex thresholds for 678 Hz probe were higher than those obtained with 226 Hz and 1000 Hz probes. CONCLUSION: There were no artifact appearance while stimulus had been click at low rate, so click can be used for the measurement of ipsilateral acoustic reflex thresholds.     

Detection of the acoustic stapedius reflex in infants using wideband energy reflectance and admittance

This study examined the measurement of the contralateral acoustic stapedius reflex in six-week-old infants and adults using wideband shifts in admittance and energy reflectance (YR). The reflex activator was bandpass noise from 2,500 to 11,000 Hz presented at a maximum spectrum level of 51 dB SPL measured in the ear canal. Reflexes were detected by calculating a cross-correlation between one-twelfth-octave measurements of YR for the highest activator level and responses to lower levels. The reflex-induced shifts in YR for the infant ears were similar in pattern to adult responses but were noisy at frequencies below 1000 Hz. Infant reflexes were more successfully detected when the cross-correlation was calculated from 1000 to 8000 Hz, whereas adult reflexes were more successfully detected for a cross-correlation from 250 to 2000 Hz. This method may be useful in capturing the most robust frequency region for acoustic reflex detection across postnatal middle ear development.     

Factors influencing the acoustic-immittance characteristics of the acoustic reflex

Measurements of the aural acoustic-immittance (admittance and impedance) characteristics of the middle-ear transmission system in humans during the quiescent (static) and reflexive states were made (N = 36) utilizing a signal-averaging technique. Three pure tones (750, 1000, and 2000 Hz) and broadband noise stimuli elicited the acoustic reflex in 2-dB steps at sound-pressure levels from 84-116 dB (tones) and 66-116 dB (noise) during ascending- and descending-intensity level runs. The contralateral middle-ear activity was monitored with a 220-Hz probe by digitizing the conductance and susceptance outputs of an admittance meter. A computer corrected for the ear-canal volume utilizing measurements made at ear-canal pressures of 0 and --350 daPa and then converted the conductance and susceptance values into admittance and impedance units. The results were reported in absolute and relative immittance units, including components, as a function of both stimulus sound-pressure level and intensity level above the acoustic-reflex threshold. The static immittance of the middle ear changed nonlinearly over time to lower admittance or higher impedance values. The influence of this static-immittance shift on the reflex magnitude was discussed. The largest mean reflex magnitude and the slowest rate of growth were observed with broadband noise, although eight of the 36 subjects demonstrated the largest reflex magnitude in response to one or more of the tonal stimuli. Although static-immittance values and acoustic-reflex thresholds were poorly correlated, the reflex magnitudes were proportional to static immittance. The variability of the reflex measures was similar to the variability of the static-immittance values. Finally, bi-directional changes in resistance during the reflexive state were observed and discussed.     

不同月龄婴儿声反射与畸变产物耳声发射测试结果分析

目的探讨不同月龄婴儿226 Hz和1000 Hz探测音的中耳声反射测试与畸变产物耳声发射（DPOAE）联合筛查的意义。方法测试对象为来泸州医学院附属医院进行听力筛查或复查的188例（350耳）3天～12月龄的婴儿,分为3天～1月龄组（125耳）,2～3月龄组（89耳）,4～6月龄组（76耳）,7～12月龄组（60耳）,分别进行226、1000Hz探测音声导抗,畸变产物耳声发射测试,对226、1000Hz探测音中耳声反射引出率和DPOAE的通过率进行比较分析。结果3天～1月龄组226、1000Hz探测音声反射引出率和DPOAE的通过率分别为81％、69％、73％;2～3月龄组分别为91％、72％、74％;4～6月龄组分别为90％、83％、79％;7～12月龄组分别为43％、66％、60％。226Hz声反射引出率与DPOAE通过率差异有统计学意义（P〈0．01）,1000Hz声反射引出率与DPOAE通过率差异无统计学意义（P〉0．05）,并且DPOAE筛查结果与1000Hz探测音的声反射结果较一致。结论1000Hz探测音声导抗测试对婴儿中耳功能的诊断价值比226Hz探测音的敏感性更高,与DPOAE协同用于婴儿听力筛查具有良好的临床价值。     

Tympanometric and acoustic-reflex studies in neonates

Tympanograms and acoustic reflexes for a broadband noise and for a 1000-Hz tone were measured in normal neonates. Notched tympanograms were typical of neonatal ears for a 220-Hz probe tone. A single-peaked tympanogram was most characteristic for a probe frequency of 660 Hz. Ipsilateral and contralateral acoustic reflexes were present more frequently for a 660-Hz probe tone compared to a 220-Hz probe tone, but acoustic-reflex thresholds were not significantly different between probe tones. As with adults, acoustic-reflex thresholds for the noise were significantly lower than for the tone, and ipsilateral reflex thresholds were lower than contralateral reflex thresholds. Reliability of acoustic-reflex and tympanometric measures was high. Age change from 2 to 4 days had no significant effect on tympanometric or acoustic-reflex characteristics. There was no apparent relation between tympanometric pattern and acoustic-reflex characteristics.     

High frequency distortion product otoacoustic emissions in children with and without middle ear dysfunction

OBJECTIVE: Distortion product otoacoustic emissions (DPOAEs) (9-16kHz) are a useful measure of the function of the cochlea, which may be damaged by ototoxic drugs during anticancer chemotherapy. As children undergoing chemotherapy may also have middle ear problems, it is necessary to know if middle ear problems would have a confounding effect on the ability of DPOAEs to assess cochlear function in the extend high frequency region (9-16kHz). The present study aimed to investigate the effect of middle ear dysfunction on DPOAEs in the extended high frequency region in young children. METHODS: The sample was comprised of 100 ears of 50 school-aged children (21 boys and 29 girls) with a mean age of 6.3 years (S.D.=0.5; range 5.3-7.3). Otoscopy, pure tone hearing screening, tympanometry, acoustic reflexes and DPOAEs for both the conventional and extended high frequencies were administered to each child under typical school screening conditions. Participants were classified into one of three groups based on immittance (tympanometry and acoustic reflex) results. They included a "pass immittance" group, a "fail immittance" group and an "undetermined" group (with a pass in either tympanometry or acoustic reflexes, but not both). DPOAE amplitudes and signal-to-noise ratios (SNRs) were measured and compared across the three groups of participants. RESULTS: The fail immittance group showed significantly smaller DPOAE amplitudes and SNRs when compared to the other two groups at frequencies ranging from 1 to 9.5kHz and at 13kHz, but not at 10, 11, 12 and 14kHz. There was no significant difference in DPOAE results between the pass immittance and undetermined groups. CONCLUSIONS: Despite the adverse effects of middle ear dysfunction, its effect on DPOAEs in the extended high frequency region was not as severe as that in the lower frequency region. Hence, assessment of cochlear function in children with a middle ear lesion in the extended high frequencies using DPOAEs should be made with caution.     

Ipsilateral and contralateral acoustic reflexes in neonates

Ipsilateral and contralateral acoustic reflexes were studied in neonates using 220 and 660 Hz probe tones and 500, 1000, 2000, and 4000 Hz activators. Activator sound pressure level was measured in all ears. Ipsilateral and contralateral reflexes were detected three times more frequently with a 660 Hz probe tone than with a 220 Hz probe tone. The maximum detection rate (76%) occurred with 1000 and 2000 Hz ipsilateral activators and the 660 probe tone. There was no significant difference between neonatal and adult ipsilateral thresholds at 500, 1000, and 4000 Hz. Neonatal intrameatal sound pressure levels for ipsilateral activators were found to be significantly higher than would be indicated from the otoadmittance meter manufacturer's specifications.     

High- and Low-Frequency Probe Tone Tympanometry in Chinese Infants

Objective To assess the utility of low- and high-frequency tympanometry in the diagnosis of middle ear dysfunction in Chinese infants. Methods Tympanograms were obtained with 226 Hz, 678 Hz and 1000 Hz probe tones from infants aged 5-25 weeks with normal auditory brainstem responses (ABRs)(15 infants,30 ears) and withprolonged wave Ⅰ latencies(17 infants, 20 ears), suggesting middle ear dysfunction, using a GSI Tympstar middle ear analyzer Version Ⅱ. Results The single-peaked tympanogram was the most characteristic type in both groups and seen in 25 ears (83.3%) in the normal ABR group and in 18 ears (90%) in the delayed wave Ⅰ group, respectively. The peak pressure, peak compensated static acoustic admittance and gradient of 226 Hz tympanometry were of no significant differences between the two groups. The 678 Hz tympanograms of admittance, susceptance and conductance demonstrated non-peak, single-, double- and tri-peaked patterns in both groups. The agreement between ABRs and 678 Hz tympanograms of admittance,susceptance and conductance were 70.0%, 58.0% and 64.0%(kappa=0.324, 0.234 and 0.118) respectively. For 1000 Hz probe tone, admittance,susceptance and conductance tympanograms showed single peaked patterns in 28 (93.3%), 25 (83.3%) and 26 (86.7%) of the 30 normal ears. Admittance, susceptance and conductance tympanograms using the 1000 Hz probe tone were flat in 15 (75%), 17(85%) and 13 (65%) of the ears in infants with prolonged wave Ⅰ latencies. For 1000 Hz admittance, susceptance and conductance Tympanograms, the agreement between tympanometry and ABR results were 90.0%, 92.0% and 86.0% with kappa at 0.783, 0.831 and 0.690, respectively. Conclusion 1000 Hz probe tone tympanometry is a promising middle ear function test for infants of 1-6 months age, while 226 Hz and 678 Hz probe tones are less efficient in detecting middle ear dysfunction in infants.     

正常婴儿1000Hz探测音及多频率扫描声导纳测试分析

目的分析正常婴儿1000 Hz探测音及多频率扫描声导纳检测的临床特征。方法对164例正常听力婴儿（250耳）的1000 Hz探测音声导纳图,用基线法分型并测量正峰声导纳值;通过声纳差（ΔB）-频率函数曲线和相位角差（Δθ）-频率函数曲线检测中耳共振频率。运用SPSS11.0软件,分年龄段分别统计正峰声导纳、共振频率和相位角差（Δθ）的平均值、标准差、中位数、5%分位数、95%分位数及95%置信区间。结果全部样本均可测得基线上正峰声导纳值,各年龄组的5%分位数均≥0.2 mmho;各年龄组共振频率从311.01～599.06 Hz递增,相位角差（Δθ）的绝对值平均值从44.52～22.84递减。结论高频率探测音声导纳检测和多频率扫描声导纳检测,充分反映婴儿中耳声学特性的转变过程,更适用婴儿的中耳功能评估。     

Clinical investigation and mechanism of air-bone gaps in large vestibular aqueduct syndrome

OBJECTIVES: Patients with large vestibular aqueduct syndrome (LVAS) often demonstrate an air-bone gap at the low frequencies on audiometric testing. The mechanism causing such a gap has not been well elucidated. We investigated middle ear sound transmission in patients with LVAS, and present a hypothesis to explain the air-bone gap. METHODS: Observations were made on 8 ears from 5 individuals with LVAS. The diagnosis of LVAS was made by computed tomography in all cases. Investigations included standard audiometry and measurements of umbo velocity by laser Doppler vibrometry (LDV) in all cases, as well as tympanometry, acoustic reflex testing, vestibular evoked myogenic potential (VEMP) testing, distortion product otoacoustic emission (DPOAE) testing, and middle ear exploration in some ears. RESULTS: One ear with LVAS had anacusis. The other 7 ears demonstrated air-bone gaps at the low frequencies, with mean gaps of 51 dB at 250 Hz, 31 dB at 500 Hz, and 12 dB at 1,000 Hz. In these 7 ears with air-bone gaps, LDV showed the umbo velocity to be normal or high normal in all 7; tympanometry was normal in all 6 ears tested; acoustic reflexes were present in 3 of the 4 ears tested; VEMP responses were present in all 3 ears tested; DPOAEs were present in 1 of the 2 ears tested, and exploratory tympanotomy in 1 case showed a normal middle ear. The above data suggest that an air-bone gap in LVAS is not due to disease in the middle ear. The data are consistent with the hypothesis that a large vestibular aqueduct introduces a third mobile window into the inner ear, which can produce an air-bone gap by 1) shunting air-conducted sound away from the cochlea, thus elevating air conduction thresholds, and 2) increasing the difference in impedance between the scala vestibuli side and the scala tympani side of the cochlear partition during bone conduction testing, thus improving thresholds for bone-conducted sound. CONCLUSIONS: We conclude that LVAS can present with an air-bone gap that can mimic middle ear disease. Diagnostic testing using acoustic reflexes, VEMPs, DPOAEs, and LDV can help to identify a non-middle ear source for such a gap, thereby avoiding negative middle ear exploration. A large vestibular aqueduct may act as a third mobile window in the inner ear, resulting in an air-bone gap at low frequencies.     

Wideband reflectance in Down syndrome

ObjectiveChildren with Down syndrome (DS) have a high incidence of middle ear disorders and congenital abnormalities of the external, middle and inner ear. Energy reflectance (ER), a wideband acoustic immittance (WAI) measurement parameter, can measure the sound energy reflected or absorbed in the ear canal over a wider range of frequencies more efficiently and faster than conventional single-tone 226 Hz tympanometry. The aim of the present study was to compare the WAI measurements of children with DS with those of typically developing, normal-hearing children according to their tympanometric findings.MethodsFour groups of children with Down syndrome (age range: 2 years and 4 months to 16 years and 3 months; mean age: 8.5 yr) with normal tympanograms (19 ears), flat tympanograms (13 ears), mild negative pressure tympanograms (6 ears between −100 and −199 daPa at the admittance peak) and severe negative pressure tympanograms (4 ears at −200 daPa or lower at the admittance peak) were assessed. All findings were compared with data obtained from 21 ears of a healthy control group (age range: 3 years and 1 month to 13 years and 11 months; mean age: 7.9 yr). The subjects underwent tympanometry with a 226-Hz probe tone frequency and ER measurements along the 200–6,000 Hz range with a chirp stimulus using the Middle-Ear Power Analyzer (MEPA3 – HearID) by Mimosa Acoustics (Champaign, IL), software, version 3.3 [38].ResultsStatistically significant differences were observed in the ER curves for some comparisons between the studied groups. There was also a negative correlation between the static acoustic admittance at the tympanic membrane level and ER measured with a chirp stimulus at 500 and 1,000 Hz. The discriminant analysis technique, which used a chirp stimulus at 1,000 and 1,600 Hz to classify the participants' data based on ER values, achieved a correct classification rate of 59.52% for participants with DS.ConclusionWhile groups with abnormal middle ear status, as indicated by tympanometry, showed higher ER values compared to the DS tymp A group and the control group, similar reflectance curves were observed between control group and the DS tymp A group. WAI shows promise as a clinical diagnostic tool in investigating the impact of middle ear disorders in DS group. However, further research is required to investigate this issue in narrower age range group and a larger sample size.     

Impedance audiometry with 3-probe frequency]

The 3-probe frequency (226, 678, 1000Hz) admittance (Y), susceptance (B) and conductance (G) tympanograms were recorded from 28 normal-hearing adults with a GSI 33 Version 2 Middle-Ear analyzer, and the 3-frequency ipsilateral acoustic-reflex thresholds were measured too. In all subjects, there were normal values of tympanometric indices, such as peak compliances, peak pressures, gradients and ear canal volumes, and of ipsilateral acoustic-reflex thresholds at a 226-Hz probe tone. From 226 to 1000Hz, Y, B and G increased in magnitude while the corresponding admittance-,susceptance- and conductance-tympanogram peak pressures (PY, PB, PG) shifted towards positive evidently. In comparison with 226 Hz, the 678-Hz static admittance (Y') and static susceptance (B') values were large but had no significant differences as compared with those of 1000 Hz. The relation among Y, B and G, among PY, PB and PG, and between Y' and B' changed as a function of probe frequency from 226 to 1000 Hz. The average reflex thresholds of 25 adults (30 ears) were 83 dB HL at 226-Hz probe frequency, 91 dB at 678 Hz, and 88 dB at 1000 Hz, using a 1000-Hz tonal activator. There were significant differences among the 3 values (all P less than 0.01). The ipsilateral acoustic reflexes from 3 adults (4 ears) were present at 226-and 678-Hz probe tones, but not at 1000 Hz.     

耳硬化症和中耳畸形患者的宽频声导抗研究

目的探讨宽频声导抗测试对耳硬化症和中耳畸形辅助诊断中的应用价值。方法收集耳硬化症组45耳,先天性中耳畸形组13耳,另有正常组76耳作为对照,所有受试者均行宽频声导抗测试,对各组峰压下的声能吸收率进行分析比较。结果峰压下,耳硬化症组的声能吸收率在917/972~1029/1091~1297/1456/1731/2059~3462/4000~5339Hz比正常组的显著减小(P<0.05)。耳硬化症患者在1kHz以下较正常组无异常切迹。峰压下,先天性中耳畸形组的声能吸收率在408~749/7336~7772Hz比正常组的显著增大(P<0.05),在1059~1224/1297/1414~1456/4000~4490Hz比正常组的显著减小(P<0.05)。69%(9/13)的先天性中耳畸形患者在1kHz以下有一切迹。结论声能吸收率鼓室图在1kHz以下出现切迹提示患者存在镫骨畸形合并锤骨和/或砧骨畸形。仅镫骨固定患者1kHz以下无切迹。宽频声导抗对于术前评估耳硬化症和中耳畸形患者中耳听骨链情况具有现实意义,可作为辅助耳硬化症和中耳畸形诊断的听力学检查之一。     

Acoustic reflex thresholds in normal and cochlear-impaired ears: effects of no-response rates on 90th percentiles in a large sample

Ninetieth percentile cutoffs for acoustic reflex thresholds (ARTs) were determined for a sample of 2,748 ears of 1,374 subjects with normal hearing and sensorineural loss of cochlear origin. All subjects had measurable hearing (less than or equal to 110 dB HL, ANSI-1969) at all three activator frequencies (500, 1000, and 2000 Hz). Cutoff values including "no responses" ("absent" reflexes at 125 dB HL) were higher than those excluding no responses when hearing losses were greater than about 55 dB. The 90th percentiles including the effects of no responses identified ears with retrocochlear involvement for hearing losses as great as about 756 dB. For greater hearing losses at the activator frequency, the no-response rate for both cochlear and retrocochlear cases is too high to enable them to be differentiated by acoustic reflex thresholds. The 90th percentiles are derived at each activator frequency collapsed across ears. It is therefore necessary to determine the probabilities that normal or cochlear-impaired ears will have one, two, or three frequencies at which the ARTs exceed their respective 90th percentiles. It was found that among normal and cochlear-impaired ears, 12.2% have one ART elevated above the 90th percentile, but only 5.6% have two or three elevated ARTs. Clinical implications are discussed.     

低频和高频探测音鼓室声导抗测试在婴儿中耳功能诊断中的作用

目的评价低频和高频探测音鼓室声导抗测试在诊断婴儿中耳功能异常中的作用。方法使用GSI Tympstar中耳分析仪，对年龄5—25周的听性脑干反应（auditory brainstem response，ABR）检查正常婴儿15例（30耳）和Ⅰ波潜伏期延长提示可能存在中耳功能异常婴儿17例（20耳），进行226、678、1000Hz探测音鼓室声导抗测试的比较。结果226Hz探测音鼓室声导纳图的静态声导纳值、图形、峰压和梯度在2组间的差异无统计学意义。678Hz探测音鼓室声导纳图、声纳图及声导图在2组中均可见无峰型、单峰型、双峰型、三峰型图形，其与ABR检查的一致率分别为70．0％、58．0％、64．0％，kappa值分别为0．324、0．234、0．118。1000Hz探测音鼓室声导纳图、声纳图及声导图在正常组中单峰型分别为28耳（93．3％）、25耳（83．3％）、26耳（86．7％），在异常组中无峰型分别为15耳（75％）、17耳（85％）、13耳（65％），其与ABR的一致率分别为90．0％、92．0％、86．0％，kappa值分别为0．783、0．831、0．690。结论1000Hz探测音鼓室声导抗测试是诊断小于25周婴儿中耳功能的较准确的检查方法，226、678Hz探测音鼓室声导抗测试则不能提供这些婴儿中耳功能的准确的信息。     

中耳功能正常与异常婴儿的宽频声导抗能量吸收率特性研究

目的：对比中耳功能正常与异常婴儿宽频声导抗（wideband acoustic immittance ,WAI）能量吸收率（wideband absorbance ,WBA）的差异,探讨宽频声导抗对婴儿中耳功能诊断的作用。方法根据高频（1 kHz）声导抗（high frequency tympanometry ,HFT ）、畸变产物耳声发射（DPOAE）及听性脑干反应（ABR）结果将3～12月龄婴儿46例分为中耳功能正常组31例（50耳）和中耳异常组15例（20耳）,用96 dB peSPL 的宽频短声（频率范围226～8000 Hz）对两组进行宽频声导抗测试,比较两组能量吸收率特性,分析中耳功能对不同频率能量吸收率的影响。结果无论外耳道压力为峰压还是0 daPa时,除8000 Hz外,中耳功能正常组婴儿的宽频声导抗能量吸收率均高于中耳功能异常组,且2000 Hz处两者差异最大。当外耳道压力为峰压时,中耳功能正常组与异常组226～6727 Hz WBA差异均有统计学意义（P＜0．05）;当外耳道压力为0 daPa时,中耳功能正常组与异常组500～6727 Hz WBA差异有统计学意义（P＜0．05）。结论中耳功能正常与异常婴儿宽频声导抗能量吸收率差异有统计学意义,宽频声导抗可作为有效检测婴儿中耳功能的方法之一。     

Ipsilateral acoustic reflex stimulation in normal and sensorineural impaired ears: a preliminary report.

Ipsilateral acoustic reflex thresholds were measured at 1,000 Hz and 2,000 Hz in 38 subjects with normal hearing and in 107 subjects with a symmetrical sensorineural hearing loss. Acoustic reflex thresholds were approximately six dB better for ipsilateral vs. contralateral stimuli for both subject groups. High ipsilateral reflex thresholds were associated with larger static compliance values in the sensorineural hearing impaired subjects. Reversed reflexes (increasing compliance with muscle contraction) were observed for ipsilateral stimulation in five per cent (two) of the normal hearing subjects, and 23 percent (25) of the sensorineural hearing impaired subjects. The number of reversed reflexes was greater for subjects with higher hearing thresholds and higher ipsilateral acoustic reflex thresholds. The results suggest that quantitative use of the ipsilateral acoustic reflex requires additional research. At present it seems prudent to use ipsilateral acoustic reflex measurements as a qualitative rather than a quantitative tool, e.g. in confirming the status of one middle ear when the other has a conductive hearing loss. However, even this limited role has a considerable clinical potential.