畸变产物耳声发射对侧抑制效应的临床应用价值

目的：为观察畸变产物耳声发射（ＤＰＯＡＥ）对侧抑制效应的临床应用价值。方法：研究以白噪声为对侧声刺激,对１７例正常人（３４耳）,１３例蜗性聋（１３耳）,９例蜗后聋（９耳）进行了ＤＰＯＡＥ及其对偶抑制效应测试。结果：蜗性聋耳的ＤＰＯＡＥ幅值较正常耳显著下降（Ｐ〈０．０１）,对偶抑制效应减弱,但与正常人差异无统计学意义（Ｐ〉０．０５）,蜗后聋耳ＤＰＯＡＥ幅值高于正常耳（Ｐ〉０．０５）,对侧抑制效应显著     

耳鸣与耳声发射

为探讨耳鸣的产生原因和客观检测手段以及耳鸣与耳声发射（ＯＡＥ）的关系，报道耳鸣患者２７３例（３０６耳）畸变产物耳声发射（ＤＰＯＡＥ）、自发性耳声发射（ＳＯＡＥ）和瞬态诱发性耳声发射（ＴＥＯＡＥ）的特点。结果提示：①耳鸣频率与ＳＯＡＥ频率不一致；②９４．８％感音神经性聋伴耳鸣患者ＤＰＯＡＥ图在相应频率有振幅下降或缺失，５９％听力正常耳鸣耳出现某些频率ＤＰＯＡＥ振幅下降和反应缺失，且不能记录到ＳＯＡＥ，而在ＳＯＡＥ频率附近ＤＰＯＡＥ有良好反应高峰。耳声发射可望用于发现早期耳蜗病变。     

畸变产物耳声发射对侧抑制效应的研究

利用ＩＬＯ９２耳动态分析仪，测试２３例（４６耳）正常青年人的畸变产物耳声发射（ＤＰＯＡＥ）和对侧窄带噪声（ＮＢＮ）的影响。结果：（１）对侧ＮＢＮ对ＤＰＯＡＥ的抑制非常明显，随ＮＢＮ强度增加ＤＰＯＡＥ幅值下降增加，二者呈显著负相关（Ｆ２为１～６ｋＨｚ，γ为－０．４９～－０．２４，均Ｐ〈０．０５，斜率０．２６～０．０８ｄＢ／１０ｄＢ）。（２）在Ｆ２为中频（１．２ｋＨｚ）且为中等强度（４５～６５ｄＢＳＰ     

短时纯音暴露对正常人畸变产物耳声发射幅值及频谱时间序 …

目的：探讨在耳蜗功能早期以微损害时畸变产物耳声发射（ＤＰＯＡＥ）幅值及频谱邓列的特征，促进ＤＰＯＡＥ的临床。方法：用１３０ｄＢＳＰＬ的４ｋＨｚ纯音对１５例听力正常人（３０耳）进行３ｍｉｎ的短时暴露，造成听力暂时性阈移后，用ＩＬＯ－９０耳声发射仪记录，分析暂时性阈移（ＴＴＳ）时ＤＰＯＡＥ的幅值，时间序列的特征，并与纯音暴露前进行对比。结果：正常人经过短时纯音暴露后，０．５，１．２ｋＨｚ纯音和宽带噪声     

短时纯音暴露对正常人畸变产物耳声发射幅值及频谱时间序列的影响

探讨在耳蜗功能早期轻微损害时畸变产物耳声发射（ＤＰＯＡＥ）幅值及频谱时间序列的特征,促进ＤＰＯＡＥ的临床应用。方法：用 １３０ｄＢ ＳＰＬ的 ４ ｋＨｚ纯音对 １５例听力正常人（３０耳）进行 ３ ｍｉｎ的短时暴露,造成听力暂时性阈移后,用ＩＬＯ－９０耳声发射仪记录、分析暂时性阈移（ＴＴＳ）时ＤＰＯＡＥ的幅值、时间序列的特征,并与纯音暴露前进行对比。结果：正常人经过短时纯音暴露后,０．５,１,２ ｋＨｚ纯音和宽带噪声的声反射阈升高,纯音暴露前后０．５、１、２ ｋＨｚ与ＢＢＮ之间的平均反射阈差值分别为（９．７８±６．９８）,（８．０４±５．５８）,（１３．０±５．５８） ｄＢ ＨＬ和（８．８２±６．２３）,（５．７５±４．４２）,（９．０５±２．２７）ｄＢ ＨＬ,声反射阈差值缩小。纯音暴露前后６ ｋＨｚＤＰＯＡＥ幅值分别为（６．００±３．４５）和（１．７２±１. ２３） ｄＢ ＳＰＬ,降低４．２８ ｄＢ ＳＰＬ,时间序列变异系数为（５．１８±１．６３）％,时间序列曲线稳定性降低,ＤＰＯＡＥ幅值与时间序列结合发现８０％的人ＤＰＯＡＥ处于异常范围。结论：ＤＰＯＡＥ的幅值与时间序列结合分析有诊断耳蜗功能早期轻微受损的临床价值。     

耳鸣与耳声发射

为探讨耳鸣的产生原因和客观检测手段以及耳鸣与耳声发射（ＯＡＥ）的关系，报道耳鸣患者的２７３例（３０６耳）畸变产物耳声发射（ＤＰＯＡＥ），自发性耳声发射（ＳＯＡＥ）和瞬态诱发性耳声发射（ＴＥＯＡＥ）的特点，结果提示：（１）耳鸣频率与ＳＯＡＥ频率不一致，（２）９４．８％感音神经性聋性耳鸣患者ＤＰＯＡＥ图在相应频率有振幅下降或缺失，５９％听力正常耳鸣耳出现某些频率ＤＰＯＡＥ振幅下降和反应缺失，且不能记录     

畸变产物耳声发射选择注意效应测试对糖尿病人听力的评价

为观察畸变产物耳声发射选择注意效应的临床应用价值对１９例控制良性的糖尿病人进行ＤＰＯＡＥ温度，并以１９例正常人作对照。结果示，正常人在对侧声刺激与视觉任务同时出现时，相对幅值增加，ＣＡＳ与视觉任务有协同作用。２例糖尿病人的ＤＰＯＡＥ在３ｋＨｚ以上频率区消失，４例的对侧抑制效应，选择注意效应及协同效应显著减弱，ＤＰＯＡＥ相对幅值显著小于正常人；３例的相对幅值均为正值，ＣＡＳ或视觉任务不但不抑制，反而     

选择注意对畸变产物耳声发射的影响

为研究高级中枢对耳蜗微机制的调控作用，对正常人１６例（３２耳）进行有和无视觉选择任务条件下的畸变学产物耳声发射（ＤＰＯＡＥ）测试，结果显示视觉任务了出现时ＤＰＯＡＥ幅值下降，Ｆ２为１，２ｋＨｚ处的ＤＰＯＡＥ幅值下降达显著性水平（Ｐ〈０．０５）。讨论了调控作用的可能机制，认为研究高级中枢和橄榄耳蜗传出神经系统对耳蜗功能的影响将有十分重要的生理和病理意义。     

畸变产物耳声发射在突发性聋在突发性聋恢复过程中的变化

目的：探讨畸变产物耳声发射（ＤＰＯＡＥ）测试对于耳蜗功能损害的检测价值。方法：ＧＳＩ－６０型耳声发射检测２仪,对３０例（６０耳）突发性聋（突聋）患者进行ＤＰＯＡＥ测试,观察其发病和恢复过程中的耳声发射（ＯＡＥｓ）变化,及其与纯间听阈变化的关系。并对患者进行治疗与随访。结果：患耳的ＤＰＯＡＥ检出率、幅值低于健耳,检出阈升高;在恢复过程中,ＤＰＯＡＥ的幅值、检出阈也随听阈一起改善;听阈的恢复率高于幅值     

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。     

自发性耳声发射与耳蜗传出调控的关系探讨

OBJECTIVE: To study the relationship between spontaneous otoacoustic emissions(SOAE) and efferent control of cochlea and their clinical significance. METHODS: SOAE, transient evoked otoacoustic emissions (TEOAE), distortion product otoacoustic emissions (DPOAE) and contralateral white noise (60 dB SPL) suppression of TEOAE and DPOAE experiments were conducted in 312 ears of 95 patients with retrocochlear impairment and/or MOCS dysfunction and 64 normal young adults. RESULTS: MOCS dysfunction was shown in 126 ears of 65 patients (130 ears) with auditory neuropathy, 2 ears of 2 patients with unilateral acoustic neuroma, 4 ears of 2 patients with hyperacusis, 14 ears of 26 patients(48 ears) with normal hearing level in unilateral or bilateral tinnitus. Stronger EOAE could be recorded in total 146 ears with MOCS dysfunction at any pure tone hearing level. SOAE could be recorded in 126 of 146 ears (86.3%) with MOCS dysfunction and 44 of 128 ears (34.3%) with normal hearing. SOAE of ears with MOCS dysfunction was mainly at frequencies from 0.693 to 3.055 kHz and SOAE of normal ears was at frequencies from 1.135 to 2.746 kHz. Average value of maximum amplitude of SOAE spectrum (-3.4 +/- 6.4) dB SPL was significantly greater than that in normal ears (-6.8 +/- 7.8) dB SPL (P < 0.01). The major frequency range of SOAE (0.693-3.055 kHz) in MOCS dysfunction ears was essentially consistent with that of efferent suppression in normal ears (0.7-3 kHz). CONCLUSION: The modulation of the cochlear active mechanisms by MOCS mainly presents in the low- and mid-frequency regions, these frequencies correspond to the frequency range of SOAE. Stronger SOAE indicates pathophysiological significance. There is a clear clinical relationship between SOAE and the efferent modulation of the cochlea.     

Effects of AC and DC stimulation on chinchilla SOAE amplitude and frequency

The effects of AC and DC current on spontaneous otoacoustic emissions (SOAEs) were studied in normal chinchillas and chinchillas with selective inner hair cell (IHC) loss. Electrical stimulation was delivered through an electrode on the round window or through an electrode in scala media. SOAE frequencies ranged from 4 to 11 kHz and amplitudes ranged from 13 to 51 dB SPL. AC simulation suppressed SOAE amplitude. The suppression contours had a narrowly tuned, low-threshold tip located above the frequency of the SOAE. AC suppression contours were similar to acoustic suppression contours except that the AC suppression contours lacked a high-threshold, low frequency tail. The lowest threshold of the AC suppression contour was 3.9 μA rms whereas the lowest acoustic suppression threshold was 19 dB SPL. AC stimulation, which induced an electrically evoked otoacoustic emission, interacted with the SOAE to generate distortion product otoacoustic emissions (DPOAEs) of up to 26 dB SPL at 2f_S−f_AC (f_S=SOAE). DPOAE amplitude increased with AC current, but saturated at high levels. DC current steps affected both SOAE frequency and amplitude. Positive current at the round window decreased SOAE amplitude and frequency whereas negative current increased SOAE frequency, but had little effect on amplitude. The effects of AC and DC current on SOAEs in animals with IHC loss were similar to those in normal chinchillas.     

Isoflurane increases amplitude and incidence of evoked and spontaneous otoacoustic emissions

The volatile anesthetic isoflurane was tested for its effect on cochlear function by means of measuring distortion product otoacoustic emissions (DPOAE) and spontaneous otoacoustic emissions (SOAE) in the mustached bat (Pteronotus parnellii parnellii). Averaged growth functions of DPOAE and spontaneous otoacoustic emissions were assessed and compared between the control group (no isoflurane application) and the isoflurane group (application of isoflurane at vaporizer settings sof about 1.5-2%). Isoflurane significantly increases the DPOAE amplitude, e.g. at a primary tone level l2 of 40 dB SPL by 10.7 dB. Additionally, the incidence of SOAEs was highly increased during application of isoflurane. The sound-evoked efferent effect on the generation of otoacoustic emissions was significantly reduced in the isoflurane group. We suggest that isoflurane might affect the postsynaptic action of acetylcholine (ACh) released by the efferent terminals of outer hair cells (OHCs). This could lead to the observed decrease of efferent suppression and to a disinhibition of cochlear amplification.     

Clinical investigation on spontaneous otoacoustic emission (SOAE) in 447 ears

OBJECTIVES: It is known that spontaneous otoacoustic emission (SOAE) is often observed in normal hearing ears, but concrete clinical application of SOAE test has been rarely reported, compared with transiently evoked otoacoustic emission (TEOAE) and distortion product otoacoustic emission (DPOAE) tests. In addition, there have been a variety of opinions concerning laterality of SOAE, and influence of gender and hearing on SOAE. The reason for this may be that each report has the small number of subjects and lacks in statistical power. Therefore, in the present study, SOAE, TEOAE and DPOAE were measured in 447 ears of subjects at various ages with different hearing level, and statistical analysis was performed to investigate the clinical significance of SOAE. MATERIALS AND METHODS: The subjects were 447 ears in 268 patients (268 ears in females, and 179 ears in males). The age of subjects ranged from 0 to 75 years (mean: 30.8 years), and there were 222 left and 225 right ears. The subjects of schoolchildren or older (414 ears) received pure-tone audiometry, and infants (33 ears) received auditory brain-stem response (ABR). SOAE and TEOAE were measured using ILO88 (Otodynamics, Version 4.20). DPOAE was measured using ILO92 (Otodynamics, Version 1.32). RESULTS: Incidence of SOAE and the number of SOAE per ear were high in the subjects at age of 50 years or younger, in those with hearing level of not more than 30 dB, in the right ear, and in females. Incidence of SOAE in the whole of normal hearing ears was approximately 38%, but the ears with SOAE had almost normal hearing of not more than 30 dB. CONCLUSIONS: SOAE is useful for objective hearing assessment. Moreover, SOAE sometimes appeared in the ears in which TEOAE or DPOAE could not be confirmed, and it might be useful for definite diagnosis of disease state to measure SOAE in addition to TEOAE or DPOAE.     

Influence of contralateral acoustic stimulation on distortion-product and spontaneous otoacoustic emissions in the barn owl

The avian auditory papilla provides an interesting object on which to study efferent influences, because whereas a significant population of hair cells in birds is not afferently innervated, all hair cells are efferently innervated (Fischer, 1992, 1994a, b). Previous studies in mammals using contralateral sound to stimulate the efferent system demonstrated a general suppressive effect on spontaneous and click-evoked, as well as on distortion-product otoacoustic emissions (DPOAE). As little is known about the effects of contralateral stimulation on hearing in birds, we studied the effect of such stimuli (broadband noise, pure tones) on the amplitude of the DPOAE 2f(1)-f(2) and on spontaneous otoacoustic emissions (SOAE) in the barn owl, Tyto alba. For the DPOAE measurements, fixed primary-tone pairs [f(1)=8.875 kHz (ratio=1.2), f(1)=8.353 kHz (ratio=1.15) and f(1)=7.889 kHz (ratio=1.1)] were presented and the DPOAE measured in the presence and absence of continuous contralateral stimulation. The DPOAE often declined in amplitude but in some cases we observed DPOAE enhancement. The changes in amplitude were as large as 9 dB. The influence of the contralateral noise changed over time, however, and the effects of contralateral tones were frequency-dependent. SOAE were suppressed in amplitude and shifted in frequency by contralateral broadband noise. Control measurements in animals after middle-ear muscle resection showed that these phenomena were not attributable to the acoustic middle-ear reflex. The finding of DPOAE enhancement is interesting, because a type of efferent fiber that suppressed its discharge rate during stimulation has been described in birds (Kaiser and Manley, 1994).     

听神经瘤的耳声发射观察

目的 观察和分析听神经瘤的耳声发射特点,为评估听神经瘤患者的耳蜗功能和选择保护听力的术式提供参考依据.方法 对20例（22耳）听神经瘤患者行纯音听阈、阻抗、听性脑干反应（auditory brainstem response,ABR）、诱发性耳声发射（evoked otoacoustic emissions,EOAE）测试及CT和（或）MRI扫描,能引出EOAE的瘤耳检测其自发性耳声发射（spontaneous otoacoustic emissions,SOAE）和传出抑制功能.结果 28.57%听神经瘤耳能引出EOAE,按其畸变产物耳声发射（distortion product otoacoustic emissions,DPOAE）特点分为三型：①“耳蜗型”3耳;②“非耳蜗型”2耳;③“混合型”1耳;“非耳蜗型”耳能引出强大的SOAE;能引出EOAE的6耳均有内侧橄榄耳蜗传出系统功能障碍.结论 EOAE可精确分析听神经瘤患者的耳蜗（外毛细胞）功能,部分听神经瘤病人存在“离断耳”现象.耳声发射（otoacousticemissions,OAE）在诊断重度感音神经性聋（包括听神经瘤病人）方面有一定潜能.     

耳声发射在低频感音神经性聋诊断中的应用

报告利用耳动态分析仪ＩＬＯ－９２，对５４例低频感音神经性聋患者进行了畸变产物耳声发射，瞬态诱发性耳声发射和自发性耳声发射测试。发现突聋和梅尼埃病人的ＴＥＯＡＥ检出率为４８％，ＤＰＯＡＥ的检出率为９１％，且有２例记录到ＳＯＡＥ波。而在不是原因听力下降组中，ＯＡＥ的检出率为１００％，且可记录到ＳＯＡＥ。     

Spontaneous otoacoustic emissions and sensori-neural hearing loss.

This study sought to clarify the clinical relevance of spontaneous otoacoustic emissions (SOAEs) and to define the hearing loss level (and frequency) at which absence of SOAE is found. Findings from 126 ears of patients with sensori-neural hearing loss showed an incidence of SOAEs in 18.25% of the cases (23 out of 126 ears). SOAEs were never found when hearing loss at 1,000 Hz exceeded 10 dB. The presence of SOAE seems to indicate a good cochlear functioning at least in the mid-frequencies. Although the incidence of SOAEs is markedly lower than that of evoked otoacoustic emissions (EOAEs), SOAE recording is shown to be a good test, rapid, non-invasive for audiological screening, the presence of SOAE confirming a hearing threshold of less than 10 dB at 1,000 Hz, the absence of SOAE being inconclusive.     

Effects of spontaneous otoacoustic emissions on distortion product otoacoustic emission

Objective: It has been reported that spontaneous otoacoustic emission (SOAE) can prolong the responses or increase the echo power of transiently evoked otoacoustic emission (TEOAE), yet the effects of SOAE on distortion product otoacoustic emission (DPOAE) have been studied less thoroughly. As most of the previous studies have not paid attention to the patient's age, sex and hearing level, they have not reflected possible effects of those factors. We studied the effects of SOAE specifically on DPOAE in the following subjects. Subjects and methods: The subjects were all females ranging in age from 19 to 24 (average: 21.4) and the 78 ears had a hearing threshold under 15 dB for 1, 2, and 4 kHz on pure-tone hearing test. IL088 (Otodynamics) was used for measurement of SOAE and IL092 (Otodynamics) for DPOAE. SOAEs were measured by time-averaging over 100 of the responses, of which those showing a clear peak 3 dB above the noise floor and being reproducible were considered as SOAE-positive. In all the ears, DPOAE responses were measured at L₁=L₂=70 dB, and in 42 ears also at L₁=L₂=60 dB and L₁/L₂=60/50 dB. The subjected ears were grouped into two by the presence or the absence of SOAE, and DPOAE amplitudes of 1, 2, and 4 kHz were compared, respectively. Results: Of the total, 39 ears were SOAE-positive and 39 SOAE-negative. Statistically no significant difference was observed in the average hearing level between the SOAE-positive and SOAE-negative groups. The hearing levels did not significantly differ in the frequencies of 1, 2, and 4 kHz, respectively, indicating that influence of the hearing level on DPOAE could be excludable. DPOAE amplitudes at L₁=L₂=70 dB in the frequencies of 1, 2, and 4 kHz were higher in the SOAE-positive group than in the SOAE-negative group. And DPOAE amplitudes were also higher in SOAE-positive group at L₁=L₂=60 dB and L₁/L₂=60/50 dB in the frequency of 1, 2, and 4 kHz, but significant differences were observed only in the frequencies of 4 kHz. By grouping the ears by the number of SOAE, we revealed the tendency that the larger the number of SOAE, the higher the DPOAE amplitudes. Conclusions: We evidenced that SOAE has significant effects on DPOAE responses. In clinical application of DPOAE measurement, therefore, the effects should be seriously taken into account.     

Influence of spontaneous otoacoustic emissions (SOAE) on acoustic distortion product input/output functions: does the medial efferent system act differently in the vicinity of an SOAE?

Otoacoustic emission (OAE) generation mechanisms reside in the active micromechanical properties of the organ of Corti, and especially in the outer hair cells (OHCs). OHCs are strongly innervated by medial efferent olivo-cochlear fibres. Decrease of the intensity of transiently evoked otoacoustic emissions (TOAEs) and modification of spontaneous otoacoustic emissions (SOAEs) during acoustic stimulation of the contralateral ear have already been shown in humans. Similar results were obtained in guinea pigs with a decrease of 2F1-F2 acoustic distortion products (DPOAEs) and a suppression of the effect with sectioning of the floor of the fourth ventricle. The present study sought to investigate the influence of contralateral auditory stimulation on DPOAEs recorded in humans. It shows a decrease in DPOAE intensity for all frequencies, at levels above 45 dB SPL of contralateral broad band noise. This effect was found at levels of contralateral BBN well below the acoustic reflex threshold, and in subjects without acoustic reflex. Moreover, the influence of transcranial transmission could be ruled out since no effect was found when contralateral BBN applied to the altered ear of totally unilaterally deaf patients. Thus, the contralateral acoustic stimulation effect on DPOAEs provides a new means of functional exploration of the medial efferent system in humans. The effect obtained is more ample at low primary frequency levels. Moreover, as DPOAEs are known to be stronger and to show more irregular input/output function patterns in the vicinity of an SOAE, the influence of contralateral auditory stimulation was studied for DPOAEs recorded at 10 Hz, 50 Hz and 150 Hz from an SOAE frequency.