豚鼠畸变产物耳声发射潜伏期的对侧抑制效应现象

目的 通过观察对侧抑制效应中畸变产物耳发射（distortion productotoacousticemissions,DPOAE)各指标的改变,探讨耳蜗生理机制及传出神经的调节机能。方法 12只健康杂色豚鼠分A、B2组,在对侧耳无声刺激及给予70dB SPL宽带噪声条件下,分别使用不同的原始纯音强度组合测定在f2＝2、4、6kHz时测试耳DPOAE之幅值及潜伏期。次日,A组动物背侧径路开放右耳听泡,圆窗膜给予60mmol/L卡因酸1μL,作用3h后拭去。给药后6h测试右耳无声刺激和给予70dB SPL宽带噪声刺激下,左耳的DPOAE幅值、潜伏期等指标。结果 ①用药前,A组对侧耳给声时以等强度原始音诱发的测试耳DPOAE各频率幅值与给声前基本无变化,而潜伏期显著延长;②用药前,B组对侧耳给声以差强度原始音（L2＝L1－10dB)诱发的测试耳DPOAE在2、4kHz的幅值与给声前相比有显著减小,潜伏期也显著延长;③A组用药后,对侧耳给声对测试耳DPOAE幅值和潜伏期均无显著影响。结论 潜伏期亦是对侧抑制研究中的敏感指标。对侧抑制效应在调制耳蜗转导机制中发挥负反馈作用。     

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。     

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。     

初始音强度差对听力正常青年人畸变产物耳声发射的影响

目的 探讨初始音强度差对听务正常青年人畸变产物耳声发射（ＤＰＯＡＥ）幅值的影响,为临床应用ＤＰＯＡＥ提供最佳的刺激强度组合。方法 用ＩＨＳ Ｖｅｒｓｉｏｎ ３．２型耳声发射仪对听务正常青年人３９耳进行了ＤＰＯＡＥ测试,分别记录Ｌ１为７５,６５,５５ｄＢ ＳＰＬ,强度差Ｌ１－Ｌ２为０,５,１０,１５,ｄＢ ＳＰＬ时,不同Ｌ１－Ｌ２值对ＤＰＯＡＥ幅值的影响。     

改装体检飞行员畸变产物耳声发射结果分析

目的探讨用纯音测听和畸变产物耳声发射对改装体检（对改飞高性能战斗机飞行员进行的全身体检,简称改装体检）飞行员听力评估的意义。方法将2008年3月～2009年2月进行改装体检的75名（150耳）飞行员按飞行时间分为A组（飞行650小时以上组40人80耳）和B组（飞行650小时以下组35人70耳）,分别进行纯音测听及畸变产物耳声发射检测．比较两组间的差异。结果根据《中国人民解放军审车毡行人员体格检查标准》．75人耳鼻咽喉专科飞行结论均为飞行合格。150耳中PTA正常128耳（85．33％,128／150）,异常22耳（14．67％,22／150）;DPOAE正常94耳（62．67％,94／150）,异常56耳（37．33％,56／150）。PTA正常的128耳中,94耳DPOAE幅值在正常范围,其余34耳（26．56％,34／128）有一个或几个频率幅值下降,其中1、3、dkHz下降耳数较多。PTA异常的22耳中。有20耳PTA曲线为3kHz和／或4kHz下降,表现为V型或U型曲线,其DPOAE听力图也表现为相应频率的幅值降低或未引出;其余2耳PTA及DPOAE曲线均表现为全频下降。两组DPOAE引出率差异无统计学意义,但在4kHz,两组的引出率均低于其他频率（P〈0．05）;在6、8kHz,A组DPOAE幅值低于B组（P〈0．05）,其余各频率两组的幅值差异无统计学意义。结论DPOAE可早期发现飞行员的噪声性听力损失,此部分人群是改飞后听力重点随访对象。     

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。     

正常新生儿畸变产物耳声发射测试

目的　了解正常新生儿畸变产物耳声发射基本特点及影响测试结果的因素。方法　采用耳声发射分析仪Celesta 5 0 3对正常新生儿 112耳及正常听力成人 12 6耳进行DPOAE听力图测试 ,Medisoft96统计学分析。结果　正常新生儿DPOAE总检出率为 86 6 % ,DPOAE听力图在 75 0、10 0 0、2 0 0 0、40 0 0Hz点与对照组检出率统计学无显著性差异。在 75 0和 40 0 0Hz各有一高峰 ,3 0 0 0Hz有一低谷 ,出生五天后DPOAE检出率明显高于出生五天内的新生儿 ,DPOAE听力图测试耗时 11分钟左右。结论　DPOAE结果受新生儿活动、新生儿天龄 ,探头放置及本底噪声等因素影响。在大群体新生儿听力筛选时 ,选择DPOAE听力图的 75 0、10 0 0、2 0 0 0及 40 0 0四个频率点作为筛选频率 ,筛选时机选择出生五天后 ,可能有较大的价值     

正常新生儿畸变产物耳声发射

目的研究新生儿畸变产物耳声发射（ＤＰＯＡＥ）听力筛选的最佳时机,了解正常新生儿ＤＰＯＡＥ的基本特征;方法应用Ｃｅｌｅｓｔａ５０３型耳声发射分析仪对２０名正常新生儿出生后１～５天逐日进行ＤＰＯＡＥ测试。结果随新生儿天龄的增加,ＤＰＯＡＥ的检出率及反应幅值逐渐提高。ｆ０为０．５ｋＨｚ时,ＤＰＯＡＥ的检出率较低,且反应不稳定。ｆ０≥０．７５ｋＨｚ时,ＤＰＯＡＥ的检出率迅速接近或达到１００％,大部分测试频率在出生１～２天的反应幅值显著低于后几天,至出生后第３天,ＤＰＯＡＥ的检出率及反应幅值均趋于稳定;结论新生儿ＤＰＯＡＥ听力筛选的适宜天龄应在其出生后３天或３天以上。０．５ｋＨｚ不宜作为新生儿ＤＰＯＡＥ的听力筛选频率。ＴＥＯＡＥ和ＤＰＯＡＥ相应频谱的反应幅值有显著相关性。两种耳声发射在新生儿听力筛选中各有优缺点     

机械纺织工人畸变产物耳声发射的临床研究

目的研究畸变产物耳声发射(distortion product otoacoustic emissions,DPOAE)在监测和早期发现噪声性聋(noise induced hearingloss,NIHL)方面的应用价值。方法检测160名(285耳)机械纺织工人(其中噪声性聋组125例224耳,有噪声接触史但纯音听阈正常者为对照组,共35例61耳)和75名听力正常人(正常对照组)的鼓室导抗图、镫骨肌反射、纯音听阈及DPOAE,比较三组的DPOAE幅值和引出率。结果①噪声性聋组DPOAE幅值及引出率均较正常对照组明显下降(P<0.05);②对照组与正常对照组比较,对照组的DPOAE幅值在4kHz处、引出率在3~6kHz处明显下降(P<0.05);③随着接触噪声工龄的延长,DPOAE引出率逐渐下降(P<0.05)。结论DPOAE可以客观地监测和早期发现噪声性聋,较纯音测听更有意义。     

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     

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     

自觉听力正常耳鸣患者纯音听力及畸变产物耳声发射临床分析

目的分析自觉听力正常耳鸣患者的纯音听力特征,并探讨自觉听力正常耳鸣患者畸变产物耳声发射(distortion product otoacoustic emission,DPOAE)测定值与纯音听阈值之间的相关性及其意义。方法 2010—2011年在我科就诊的以耳鸣为第一主诉但无明显自觉听力障碍患者114例(190耳),对所有入组患者进行纯音测听及DPOAE检测。分析DPOAE测定值与纯音听阈值之间的相关性,并结合其发病的可能危险因素进行相关分析。结果自觉听力正常的耳鸣患者中,听力异常可达76.84%(146/190)。纯音测听表现为:高频下降型46.31%(88/190);低频下降型14.73%(28/190);正常23.15%(44/190);其它类型15.78%(30/190)。其危险因素主要为:噪声接触,疲劳和/或精神压力、其他基础疾病等。所有频率(f0)的DPOAE幅值与各频率纯音听阈间存在负相关,且有明显的频率对应关系。结论自觉听力正常的耳鸣患者存在一定程度的听力损失,尤其以高频听力下降为多见。DPOAE测定值与其纯音听阈之间呈明显的负相关关系,且DPOAE测试频率与纯音听阈频率间存在明显的对应关系,DPOAE检测作为一种客观指标,可以在一定程度上反映自觉听力正常耳鸣患者的听力损失程度,有一定的临床应用价值。     

畸变产物耳声发射测试对噪声性聋诊断的敏感度和特异度

目的 探讨畸变产物耳声发射测试对噪声性聋的诊断价值。方法 对115名军人（204耳）进行DPOAE幅值测试,采用两个等强度L1＝L2＝70dB SPL的纯音信号f1、f2＝1．2。测试1、2、4kHz和6kHz DPOAE幅值,根据DPOAE幅值是否大于或小于标准值,判断听力正常与否。并同纯音听阈进行对照。结果 1、2、4和6kHz各频率的敏感度分别是70％、67％、85％和73％;特异度分别是71％、66％、84％和75％。结论 DPOAE幅值测试用于诊断噪声性聋,缺乏足够的敏感性和特异性,单一的DPOAE幅值测试,不能诊断噪声性聋。     

改装体检直升机与歼击机飞行员听力分析

目的比较改装体检直升机与歼击机飞行员听力学检查结果,初步了解不同机种飞行员的听力差异。方法对进行改装体检的直升机和歼击机飞行员各41名进行纯音听阈和畸变产物耳声发射检查,比较两组结果。结果根据《中国人民解放军空军飞行人员体格检查标准》,82名飞行员耳鼻咽喉专科飞行结论均为飞行合格。两组飞行员双耳0.25～8kHz平均听阈均正常,其差异无统计学意义(P>0.05);两组1～8kHz DPOAE幅值均正常,在3～4kHz,歼击机组右耳的DPOAE幅值明显低于直升机组(P<0.05);直升机组和歼击机组高频PTA异常率分别为14.63%和24.39%,两组比较差异无统计学意义(P>0.05)。直升机组和歼击机组高频DPOAE异常率分别为34.15%和58.54%,两组比较差异有统计学意义(P<0.05)。结论改装体检的直升机飞行员与歼击机飞行员的听力状况无显著差异,但歼击机飞行员高频DPOAE异常率高,潜在听力损失的可能性更大。     

Contralateral suppression of distortion-product otoacoustic emissions declines with age: a comparison of findings in CBA mice with human listeners

OBJECTIVES/HYPOTHESIS: The auditory efferent system plays presumed roles in enhancing signals in noise, maintaining the cochlea for optimal acoustic signal processing, and may have a protective role in preserving auditory function in the face of ototoxic events. The objective of the study was to measure age-related changes of the medial olivocochlear efferent system in mice by comparing distortion-product otoacoustic emissions generated with and without contralateral white noise stimulation. Consistent with prior work, distortion-product otoacoustic emissions were typically reduced in magnitude when white noise was presented to the contralateral ear. This contralateral suppression is attributed to activation of the medial olivocochlear efferent system, which has an inhibitory effect on the cochlear hair cell system. By studying contralateral suppression on cochlear output in subjects of different ages, it is possible to describe aging effects on the medial olivocochlear system. STUDY DESIGN: CBA mice were divided into three age groups: young adult, middle-aged, and old-aged animals (21, 13, and 22 animals per group, respectively), and auditory brainstem responses were obtained before distortion-product otoacoustic emission testing to assess overall hearing abilities. METHODS: 2f1-f2 distortion-product otoacoustic emission recordings were obtained from individual subjects (anesthetized with ketamine/xylazine) in each age group under two conditions: 1) in quiet and 2) in the presence of a contralaterally applied wideband noise. RESULTS: Principal findings were that distortion-product otoacoustic emission levels decreased with age for mice in a way similar to humans, when correcting for the absolute difference in life spans. In addition, contralateral suppression declined in middle-aged and old-aged groups relative to the young adults for mice in a manner similar to humans. The contralateral suppression decline at low frequencies preceded that of the decline in distortion-product otoacoustic emissions with age. CONCLUSION: Functional decline of the medial olivocochlear efferent system with age precedes outer hair cell degeneration. Loss of medial olivocochlear suppressive function may play a role in the development of presbycusis in both clinical cases and animal models.     

The effect of impulse noise on distortion product otoacoustic emissions

The aim of this study was the evaluation of distortion product otoacoustic emissions (DPOAEs) before and after noise exposure from shooting, and the comparison of DPOAEs with pure-tone audiometry. Thirteen young male police officers were exposed to impulse noise from shooting, without using earplugs. Standard pure-tone audiometry, tympanometry, and DPOAEs were performed before exposure and at one hour post- and 24 hour post-exposure. In the one hour post-exposure testing mean pure-tone thresholds were elevated in the 1–8 kHz frequency zone and DPOAE levels were reduced at several frequencies. DPOAEs were more affected at 3 kHz or lower, whereas pure-tone thresholds were more affected at higher frequencies. After the final examination, non-significant partial shifts at high frequencies on both tests remained. Pure-tone audiometry was overall more sensitive, but DPOAEs provided additional information about the cochlear status of certain ears. These data suggest that besides behavioral testing, DPOAEs may play a role as a fast, objective, and easy to perform test for monitoring subjects exposed to impulse noise.     

Hearing evaluation with distortion-product otoacoustic emissions in young patients undergoing haemodialysis

Sensorineural hearing loss is frequently reported in young patients with chronic renal failure having haemodialysis. The effect of a single session of haemodialysis on hearing acuity was assessed prospectively in nine children with end-stage renal disease using pure-tone audiometry (PTA) and distortion-product otoacoustic emissions (DPOAEs). Results were compared with those obtained from nine audiologically normal healthy children also tested with PTA and DPOAEs twice during a 4-h interval. Sensorineural hearing loss of unknown aetiology was found in 55.5% of renal patients, mainly in the higher frequencies. Patients on HD had mean PTA thresholds significantly poorer than those of the control group in the frequency range 1000–12 000Hz (P < 0.05). Their mean DPOAE amplitudes were significantly lower in all frequencies > 1184 Hz (P < 0.05). Furthermore, patients' ears with normal PTA thresholds between 250 and 4000 Hz also had decreased DPOAE amplitudes. No significant changes in PTA thresholds or DPOAE amplitudes were encountered in renal patients before and after a HD session (P > 0.05). Changes in PTA thresholds or DPOAE amplitudes were not significantly different than those in the control group (P > 0.05). In conclusion, sensorineural hearing loss of unknown origin, especially in high frequencies, is frequent in young renal patients under HD and single HD sessions do not seem to alter the hearing acuity of these patients. DPOAEs seem to be more sensitive to incipient cochlear damage than behaviour thresholds in monitoring renal patients.