畸变产物耳声发射与瞬态诱发耳声发射的相关性观察

目的：探讨畸变产物耳声发射（DPOAE)和瞬态诱发耳声发射(TEOAE)的特点和相关性。方法：以20例（40耳）耳科正常青年人观察噪声暴露前后在无对侧抑制（NCS)状态下和有对侧抑制（CS)状态下TEOAE的频带信噪比、频带反应幅值，与DPOAE的2f1-f2幅值、信噪比相互间的相关性。结果：DPOAE与TEOAE虽由不同的刺激声所引出，有各自的图形特征，但在绝大多数相近频率点上，其测量值有较好的相关性，形成一定的数量关系。结论：TEOAE测试较为快捷并有中频优势，而DPOAE则有很好的频率特异性和高频优势。二者幅值及信噪比间有良好的相关性，可得出有统计意义的线性回归方程参数，听觉损害，噪声性。     

应用畸变产物耳声发射和扩展高频测听对顺铂耳毒性的临床研究

目的：应用0．5—16kHz畸变产物耳声发射(distortion product otoacoustic emissions,DPOAE)和扩展高频测听对顺铂耳毒性进行临床研究。方法:对24例应用顺铂进行初次化疗的妇科肿瘤病人于化疗前后分别进行0．5—16kHz DPOAE、常频纯音测听及扩展高频测听检查，比较DPOAE和常频纯音测听、扩展高频测听的结果。结果：顺铂化疗后扩展高频区纯音听阈升高，DPOAE在3kHz、4kHz处及扩展高频区下降明显。结论：常频DPOAE较常频纯音测听更敏感，和扩展高频测听检查一样均可用于顺铂耳毒性的监测。扩展高频DPOAE可能比常频DPOAE更敏感。DPOAE与纯音听闻可能并非一一对应关系。病人对顺铂的易感性可能随着年龄的增加逐渐减低。     

豚鼠噪声暴露后畸变产物耳声发射与外毛细胞的改变

为观察豚鼠噪声暴露后畸变产物耳声发射（ＤＰＯＡＥ）与内耳毛细胞的改变，将１６只健康豚鼠分为３组，正常对照组３只，噪声后即刻组３只，７ｄ组１０只。暴露于１１５ｄＢ ＳＰＬ模拟潜艇机舱噪声中４ｈ，暴露后即刻及７ｄ检测ＤＯＰＡＥ听力图及Ｉ／Ｏ函数曲线，光镜及扫描电镜观察耳蜗毛细胞的改变。暴露即刻组ＤＰＯＡＥ振幅消失（Ｐ〈０．０１），７ｄ后又恢复至暴震前的基线水平（Ｐ〉０．０５）。光镜及扫描电镜显示耳蜗２     

早产儿畸变产物耳声发射特征研究

目的　研究早产儿畸变产物耳声发射 (distortionproductotoacousticemissions,DPOAE)幅值及检测通过率随孕龄 (postconceptionalage ,PCA)变化的趋势 ,探讨以耳蜗为主的外周听觉系统的发育过程。方法　PCA2 8～ 36周的早产儿 31人 (5 9耳 )和PCA37～ 4 1周的足月新生儿 19人 (35耳 )在出生后 3天～ 1周行DPOAE初测 ,对DPOAE初测未通过耳在 1周后进行复测 ,若复测未通过 ,于一周后再行复测 ,将全部测试结果按检测时PCA分成PCA <30周、PCA 30～周、PCA 32～周、PCA 34～周及PCA≥ 37周组 ,分析DPOAE幅值及通过率与检测时PCA的关系。结果　孕龄 <30周至 >37周 ,DPOAE通过率、各频率幅值呈现逐渐上升的趋势 ,且在孕龄 35周后趋于稳定。孕龄 <30周组通过率为 2 5 % ,≥ 37周组为 10 0 %。结论　外周听觉系统功能随PCA增加逐步完善 ,至PCA35周后发育趋于稳定 ,对PCA36周之前的早产儿行DPOAE检测时 ,其阳性结果 (未通过 )可能是生理性的 ,并非永久性听力障碍 ;早产儿的筛查时机宜选择理论上的PCA接近或达到足月的时间     

畸变产物耳声发射的临床研究

畸变产物耳声发射（distortionProductotoacousticemissions，DPOAEs）为由两个纯音（F_1，F_2）同时刺激诱发的、由耳蜗外毛细胞能动活动产生的、在外耳道记录到的一种声能。与其它耳声发射相比其用于临床有以下优点：①潜伏期短；②可以连续评价任何频率，尤其是1～8kHz频率范围耳蜗功能；③可以完全评价刺激阈或刺激阈上水平的耳蜗功能（输入／输出功能曲线）；④听阈高达45～55dBHL，患者可以检测出，而瞬态诱发耳声发射（TEOAES）当听阈大于30dBHL时则测不出’‘’。所以DPOAES越来越多地受到人们的重视。巨DPOAES用于临…     

豚鼠畸变产物耳声发射的检测

目的 :建立稳定可靠的检测动物畸变产物耳声发射的方法。方法 :采用预先手术切除耳屏软骨 ,加用自制探头套管 ,选择复合麻醉等改良方法 ,测量健康杂色豚鼠 7只 ( 13耳 ) 2、4、6k Hz畸变产物耳声发射( DPOAE)输入输出 ( I/ O )曲线、潜伏期等指标。结果 :各频率 DPOAE引出率均为 10 0 % ,I/ O曲线最大幅值分别为 ( 2 7.2 4± 4 .15 ) d B SPL ,( 2 7.98± 4 .0 5 ) d B SPL和 ( 4 1.4 5± 1.2 0 ) d B SPL ;潜伏期为 ( 2 .0 6± 0 .2 1) m s,( 1.5 2±0 .16) ms和 ( 1.3 7± 0 .0 8) m s。结论 :改良法豚鼠 DPOAE检出率高 ,振幅大 ,各指标结果重复性好 ,适用于动物DPOAE的研究。     

钻井工人畸变产物耳声发射的检测

目的：了解畸变产物耳声发射（ＤＰＯＡＥ）在监测噪声性聋方面的应用价值。方法：检测１０２例（１９５耳）钻井工人ＤＰＯＡＥ的幅值和引出率。结果：钻井工人ＤＰＯＡＥ的幅值和引出率均较对照组明显下降;随着接触噪声工龄的延长,ＤＰＯＡＥ的引出率逐渐下降;纯音测听正常的接触噪声者与正常人相比,ＤＰＯＡＥ的幅值及引出率亦明显降低;ＤＰＯＡＥ高频段引出率与相应频段的纯音听阈存在着负相关。结论：ＤＰＯＡＥ能较好地反     

新生儿畸变产物耳声发射测试

用ＧＳＩ６０ＤＰＯＡＥ仪对２０例（４０耳）新生儿进行畸变产物耳声发射（ＤＯＰＡＥ）测试。结果显示，在ｆ１≤１ｋＨｚ时ＤＯＰＡＥ检出率很低，而当ｆ１位于１．４￣４．０ｋＨｚ时，检出率大于９０％；低频率的ＤＯＰＡＥ辐值较低，在ｆ１位于１．４￣４．０ｋＨｚ范围内幅值较高。提示新生儿低频段ＤＰ易受噪声、刺激声强度、受试者的自身代谢活动、中耳功能及中耳对耳蜗反应的传输功能的影响。因此，在用ＤＰ进行新生儿听力     

畸变产物耳声发射检测职业性听力损伤的可行性研究

目的 探索畸变产物耳声发射（DPOAE）检测、评估和诊断职业性听力损伤的可行性和临床应用价值。方法 选36例（72耳）噪声暴露青年工人作为实验组，11例（22耳）正常青年人作为对照组，进行纯音听阈和DPOAE幅值、值嗓比和引出率测试。结果 实验组纯音听阈测值在全部频率点均明显提高，与对照组比较有显著性差异（P〈0．05或P〈0．01）。实验组DPOAE幅值和值嗓比在全部频率点均明显下降，与对照组比较有显著性差异（P〈0．01）。实验组DPOAE总引出率下降，与对照组比较有显著性差异（P〈0．01）。f0为1．4、8kHz时，DPOAE频点引出率无明显下降（P〉0．05），而其他频点均明显下降，与对照组比较有显著性差异（P〈0．05或P〈0．01）。结论 用DPOAE测试法检测、评估和诊断职业性听力损伤是可行的，有临床应用价值。其最佳的测试指标为DPOAE幅值、信噪比和总引出率。     

早产儿畸变产物耳声发射的特性分析

目的 :研究早产儿畸变产物耳声发射 (DPOAE)的幅值、信噪比、本底噪声等基本特性。方法 :应用DP2 0 0 0型耳声发射仪对 31例早产儿 (5 9耳 )和 19例足月新生儿 (35耳 )在出生后 3d～ 1周内行DPOAE检测。结果 :早产儿DPOAE反应幅值曲线有一峰点 (f2 =15 87Hz)和一谷点 (f2 =4 0 0 0Hz) ,早产儿各频率反应幅值均低于足月新生儿相应频率 (P <0 .0 5 ) ;早产儿DPOAE信噪比SNR于f2 =4 0 0 0Hz处最高 ,f2 =10 0 0Hz处最低 ,4 0 0 0Hz、3175Hz及 15 87Hz、12 6 0Hz、10 0 0Hz处SNR均低于足月儿相应水平 (P <0 .0 5 ) ;早产儿DPOAE本底噪声在低频段 (f2 =12 6 0Hz、10 0 0Hz)显著高于其他频率 ,4 0 0 0Hz处噪声水平最低 (P <0 .0 1) ,3175Hz、2 5 2 0Hz及 2 0 0 0Hz处早产儿组噪声水平均低于足月儿组 (P <0 .0 5 )。结论 :早产儿DPOAE反应幅值、信噪比及本底噪声与足月儿相比差异均有统计学意义。该差异与耳蜗外毛细胞发育过程相关 ,还可能与中耳及外耳的发育有关     

豚鼠噪声暴露后畸变产物耳声发射及神经元特异性烯醇化酶表达的观察

为观察豚鼠暴露于强噪声后畸变产物耳声发射(DPOAE)及神经元特异性烯醇化酶(NSE)的变化,选用13只Preyer's反射正常的健康豚鼠,分为二组,8只噪声暴露组,5只为NSE表达对照组。噪声强度115dB(A),连续暴露4小时,DPOAE幅值于噪声暴露前后进行测试,结果DPOAE幅值噪声暴露前后差异明显(P<0.001),豚鼠内耳内、外毛细胞及螺旋神经细胞胞浆、隧道贯穿纤维NSE免疫组化反应均呈阳性表达,暴震前后无明显变化。结果提示豚鼠接受短时间强噪声刺激后,DPOAE幅值的下降为暂时阈移,而内耳神经元及其末梢未受损伤。     

Isoflurane anesthesia suppresses distortion product otoacoustic emissions in rats

A commonly used anesthetic, isoflurane, can impair auditory function in a dose-dependent manner. However, in rats, isoflurane-induced auditory impairments have only been assessed with auditory brainstem responses; a measure which is unable to distinguish if changes originate from the central or peripheral auditory system. Studies performed in other species, such as mice and guinea-pigs, suggests auditory impairment stems from disrupted OHC amplification. Despite the wide use of the rat in auditory research, these observations have yet to be replicated in the rat animal model. This study used distortion product otoacoustic emissions to assess outer hair cell function in rats that were anesthetized with either isoflurane or a ketamine/xylazine cocktail for approximately 45?min. Results indicate that isoflurane can significantly reduce DPOAE amplitudes compared to ketamine/xylazine, and that responses were more variable with isoflurane than ketamine/xylazine over the 45-min test period. Based on these observations, isoflurane should be used with caution when assessing peripheral auditory function to avoid potentially confounding effects.     

噪声暴露工人畸变产物耳声发射和扩展高频测听的研究

目的 :分析畸变产物耳声发射 (DPOAE)和常频纯音测听、扩展高频测听的关系 ,借以探讨DPOAE的产生机制以及在噪声性听力损伤的监测和早期诊断中的应用价值。方法 :对 4 2例耳科正常人 (对照组 )和 2 0例噪声暴露工人 (实验组 )进行 0 .5～ 16 .0kHzDPOAE、常频纯音测听及扩展高频测听的检测 ,比较对照组和实验组DPOAE和常频纯音测听、扩展高频测听的结果。结果 :实验组纯音听阈在 6 .0kHz处和扩展高频区下降明显 ,与对照组比较 ,差异有显著性意义 (P <0 .0 5 ) ;DPOAE幅值在 4 .0、6 .0和 11.2kHz处下降明显 ,与对照组比较 ,差异均有显著性意义 (P <0 .0 5 ) ;而在 12 .5、14 .0、16 .0kHz 3个频率处两组差异无显著性意义 (P >0 .0 5 )。结论 :常频DPOAE检查可用于噪声性聋的早期诊断和监测。DPOAE可能来源于对应频率区及较高频率区耳蜗外毛细胞 ,其产生部位和机制尚待深入研究     

畸变产物耳声发射对耳蜗性聋和耳蜗后性聋的鉴别诊断意义

目的 探讨畸变产物耳声发射（DPOAE）鉴别诊断耳蜗性聋和耳蜗后性聋的意义。方法 采用ILO96耳动态分析仪对49例耳蜗性聋和4例耳蜗后性聋进行DPOAE测试。结果 耳蜗性聋组的DPOAE图显示出DPOAE幅值随纯音听阈的升高有不同程度的下降,并显示出很好的频率特异性,当纯音听阈＞50dBHL时,DPOAE消失。耳蜗后性聋组的DPOAE图显示出的DPOAE幅值变化不明显,仍在正常范围,与纯音听阈长吭程度缺乏相对应关系。结论 DPOAE是一种有效的辅助性鉴别诊断耳蜗性聋和耳蜗后性聋的方法。     

f2与f1比值对畸变产物耳声发射幅值的影响

目的 探索不同f2/f1比值对DPOAEs幅值的影响,寻找最佳的测试参数,以得到最大的DPOAEs测值。方法 对12例(24耳)正常青年人进行不同f2/f1比值条件下的DPOAEs幅值测试。结果 当f2/f1=1.220时,DPOAEs幅值最大(P<0.05或<0.01)。当f2/f1=1.232时,除了f2=2002Hz处以外,其DPOAEs幅值与f2/f1=1.220时无显著性差异(P>0.05)。其他f2/f1值的DPOAEs幅值均较低,多数测值与f2/f1=1.220时相比均有显著性差异(P<0.05或P<0.01)。结论 f2/f1=1.220～1.232时,DPOAEs测值最大,此范围为最佳测试参数值。     

次声波对豚鼠畸变产物耳声发射幅度的影响

目的观察强次声波暴露后豚鼠畸变产物耳声发射(DPOAE)的变化情况.方法将15只豚鼠置于频率8Hz、强度为135dB SPL的次声声场中连续暴露90分钟.分别于强次声波暴露前及暴露后即刻(2h内)、2天和5天做畸变产物耳声发射测试.结果强次声波暴露后豚鼠DPOAE的幅度值在各个频率段与暴露前相比均有明显的降低(p＜0.01),随着时间的推移,各个频率的幅度虽有一定的恢复,但仍明显低于暴露前水平(p＜0.01).结论强次声波可导致豚鼠耳蜗外毛细胞功能明显减退.     

Changes to spontaneous otoacoustic emissions (SOAEs) due to cisplatin administration

We investigated the influence of cisplatin on spontaneous otoacoustic emissions (SOAEs) by measuring SOAEs, before and after cisplatin administration, in 18 ears of nine patients (one female and eight males) who had received chemotherapy with cisplatin for a brain tumor. No hearing loss was observed after cisplatin administration in eight ears. Before cisplatin administration SOAE was present in four out of these eight ears, and only mild frequency fluctuation was observed even after administration. In 10 ears, sensory neural hearing loss was observed after cisplatin administration. Before cisplatin administration SOAE was present in four out of these 10 ears, and SOAE decreased or disappeared in three ears after administration. In two ears, SOAE was not present before cisplatin administration, but newly appeared after administration. It was indicated that SOAE principally disappeared at the frequencies where the region of the outer hair cells responsible for the same frequencies was injured, but new SOAEs appeared at the frequencies where the region of the outer hair cells was not injured after cisplatin administration.     

Effects of extremely low frequency electromagnetic fields on distortion product otoacoustic emissions in rabbits

Objective

Humans are continuously exposed to extremely low frequency (ELF), electromagnetic fields (EMF), transmitted from the common sources like power stations, electric transmission lines, communication and radio-television signal transmission units. The present study aimed to assess the effects of 50 Hz ELF-EMF of 5.068 and 10.182 kV/m electric fields, which refer to the lower and upper intensity limits beyond which hazardous effects can be observed, on the auditory functions of rabbits via Distortion Product Otoacoustic Emission (DPOAE) recordings.

Methods

The study was performed on 20 healthy adult female New Zealand White rabbits randomly divided into two groups and applied 50 Hz ELF-EMF with either 5.068 kV/m (Group 1) or 10.182 kV/m (Group 2) of electric field for 3 h/day during 14 days. DPOAE responses recorded on the 0th day before exposure (B-EMF) and on the 6th (A-EMF-6th) and 14th (A-EMF-14th) days after exposure (AE). Mean stimulus intensity and emission amplitudes at 1.0–8.0 kHz were analyzed.

Results

In Group 2 rabbits, on 6th and 14th days, the DPOAE amplitudes were observed as increased at 1.5–4.0 kHz (at 2.0 and 4.0 kHz significantly) than B-EMF values. At 6.0 kHz, A-EMF-14th amplitudes were significantly lower than A-EMF values.

Conclusion

These results suggest that ELF EMFs might affect hearing functions by frequency dependent manner. Higher ELF EMFs exposure caused increase of cochlear activity. Ototoxic effect of 10.182 kV/m ELF EMFs may begin at the basal turn of the cochlea by reducing DPOAEs at high frequencies.     

Test-retest repeatability of distortion product otoacoustic emissions

OBJECTIVES: Distortion product otoacoustic emissions (DPOAE) have become part of routine audiological diagnostics. The large scale of clinical DPOAE applications, such as screening of hearing in infants, objective estimation of hearing status, distinction between cochlear and retrocochlear origin of sensorineural hearing loss, exclusion of psychogenic hearing loss, monitoring of hearing during administration of ototoxic drugs, and others illustrates the significance of this audiological tool. In all diagnostic tests, knowledge about the procedure's test-retest repeatability is of crucial importance, to allow for distinction between measurement deviations and true physiological or pathological changes in monitoring over time. DESIGN: Measurements of DPOAE were performed in triplicate in 80 normally hearing ears of 40 subjects. Both immediate remeasurements with the ear probe left in place [single-fit mode (SF-mode)] and remeasurements after approximately 5 to 10 days [multiple-fit mode (MF-mode)] were included. DPOAE primary tone levels were varied in 5 dB steps from L2 = 60 to 20 dB SPL (L1 = L2 x 0.4 + 39 dB SPL) and within the frequency range f2 = 1 to 6 kHz. Repeatability of DPOAE was evaluated by the standard error of measurement (Sm), reliability (Cronbach alpha), absolute differences between measurements, 95% confidence intervals, and repeatability standard deviations. RESULTS: Sm averaged 0.67 dB over all frequencies and primary tone levels in the SF-mode, and 1.44 dB in the MF-mode, respectively. As expected, test-retest repeatability declined with decreasing primary tone levels; however, repeatability values were still mostly satisfactory with the lower primary tone levels. For the exemplary primary tone level combination of L1/L2 = 63/60 dB SPL, which is close to common clinical paradigms, the difference between two DPOAE measurements under the reported test conditions could be considered statistically significant (p = 0.05) if it exceeded 0.7 to 1.3 dB in the range 1 to 5 kHz and 2.3 dB for 6 kHz in the SF-mode, when compared with 1.8 to 2.7 dB for 1 to 5 kHz and 3.7 dB for 6 kHz in the MF-mode. Signal to noise ratio (SNR) did not seem to have a large influence on repeatability, as long as SNR was within 6 to 35 dB, which covers the range of most clinical DPOAE measurements. CONCLUSIONS: The DPOAE-test-retest study presented here is to our knowledge the first, which combines variation of primary tone levels, assessment of both SF- and MF-modes, and comparison of the two modalities within the same subjects. Although the measurements were conducted under practical conditions resembling the clinical setting, repeatability was generally good. The widely used minimum SNR of 6 dB seems to be a recommendable criterion when considering both practicability and measurement quality under clinical conditions. The current findings underline the suitability of DPOAE as a monitoring tool of cochlear status over time. The data are intended to assist the clinician and the scientist in the correct interpretation of DPOAE level changes in the test-retest situation.