新生儿和正常青年人瞬态诱发耳声发射的频谱分析

选用短声及短音１ｋＨｚ和２ｋＨｚ作为瞬态刺激声，对１８名正常产新儿及１８名正常青年人进行诱发耳声发射测度，并将所测得的瞬态诱发耳声发射（ＴＥＯＡＥ）波形进行频域分析。结果表明：两年龄组及三种刺激声的ＴＥＯＡＥ检出率比较差异无显著性，但新生儿组短声ＴＥＯＡＥ检出率（９１．７％）低于国外资料报道，提示生后４天内测试ＴＥＯＡＥ会影响检出率。频谱分析表明：两年龄组及三种刺激声的ＴＥＯＡＥ频谱带宽间比较差异     

高频耳蜗性聋诱发耳声发射测试结果分析

对高频耳蜗性聋耳及正常耳进行短声诱发的瞬态耳声发射（ＴＥＯＡＥ）及脑干诱发电位（ＡＢＲ）测试。结果：①正常组ＴＥＯＡＥ的频率主要成分为０．５－５ｋＨｚ之间，最大能量频谱在１－２ｋＨｚ范围内。②ＴＥＯＡＥ频谱与纯音听力图形状之间有密切关系。③正常组ＴＥＯＡＥ的输入输出函数呈非线型特点，在高刺激强度下呈饱和倾向。患者组ＴＥＯＡＥ与ＡＢＲ的增长率均可见在高刺激强度显著高于正常组的特点。提示ＴＥＯＡＥ的异     

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     

学龄前儿童及青年诱发耳声发射的测试及意义

本文对正常学龄前儿童及青年用短音及短声进行瞬态诱发耳声发射测试，并对ＥＯＡＥｓ时域图形的诸参数进行分析比较，结果表明：ＥＯＡＥｓ的各参数明显受解剖及生理因素影响，故在对其结果进行分析时要考虑年龄因素，在同等强度下，以短音１ｋＨｚ刺激时ＥＯＡＥｓ振幅最大，潜伏期最大，ＥＯＡＥｓ的信号易于辨认，提示以短音１ｋＨｚ作为ＥＯＡＥｓ测试的刺激声测试效果最佳。     

正常听力青年人诱发性耳声发射测试

本文利用耳声发射分析仪ＣＥＬＥＳＴＡ５０３对２０名正常听力青年人进行了ＤＰＯＡＥ和ＴＥＯＡＥ测试，结果发现平均ＤＰＯＡＥ图中有两个反应高峰，分别位于１ｋＨｚ和６ｋＨｚ附近，两峰之间于３ｋＨｚ左右有一反应低谷。左右耳及性别差异对ＤＰＯＡＥ无显著性影响。ＤＰＯＡＥ的反应幅值随两个初始纯音强度的增加而升高，平均检测阈值在３０～４５ｄＢＳＰＬ之间。当初始音强度≤７０ｄＢＳＰＬ时，平均Ｉ／Ｏ函数曲线未见明显饱和现象。若采用不等强度的初始纯音（Ｌ１＝７０ｄＢＳＰＬ，Ｌ１－Ｌ２＝５ｄＢ）刺激，在中频部分（１．５～４ｋＨｚ）可获得较等强度初始纯音刺激时高的ＤＰＯＡＥ反应。由８０ｄＢｐｅＳＰＬ短声诱发的ＴＥＯＡＥ检出率为１００％，平均幅值４．１１±３．９９ｄＢＳＰＬ（ｘ±ｓ）。两种耳声发射之间有显著相关性。     

不同分娩方式新生儿听性行为反应分析

目的 探讨非听力因素对新生儿听性行为反应的影响,为提高新生儿行为测听法的灵敏度和特异性提供参考。方法 １０２名正常新生儿按分娩方式为顺产组４２例,剖宫产组６０例,经瞬态诱发性耳声发射（ｔｒａｎｓｉｅｎｔ ｅｖｏｋｅｄ ｏｔｏａｃｕｓｔｉｃｅｍｉｓｓｉｏｎ,ＴＥＯＡＥ）测试;后声场给声,刺激声分别为３ｋＨｚ纯音、高频窄带噪声及白噪声,声强为９０ｄＢＳＰＬ分析恒定强度下眼睑反应、头颈反应、面部反应、     

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。     

缺氧缺血性脑病新生儿瞬态诱发耳声发射测试

目的了解应用瞬态诱发性耳声发射（ｔｒａｎｓｉｅｎｔｅｖｏｋｅｄｏｔｏａｃｏｕｓｔｉｃｅｍｉｓｉｏｎｓ,ＴＥＯＡＥ）对正常新生儿高危新生儿行听力筛查的可行性。方法采用ＳＦ－Ⅰ型耳声发射接受器与ＣｏｍｐａｃｔＡｕｄｉｔｏｒｙＴＩＰ－３００电反应测听仪联合记录,对２０名正常新生儿及３６名缺氧缺血性脑病（ｈｙｐｏｘｉａ－ｉｓｃｈｅｍｉｃｅｎｃｅｐｈａｌｏｐａｔｈｙ,ＨＩＥ）新生儿进行ＴＥＯＡＥ和ＡＢＲ测试。结果ＨＩＥ患儿ＴＥＯＡＥ多表现为阈值升高或波缺失,ＴＥＡＯＥ能否出现与ＡＢＲ之Ｖ波阈值密切相关,重度ＨＩＥ的ＴＥＯＡＥ出波率较轻度者明显减低。结论ＴＥＯＡＥ可早期发现缺氧等高危因素所致听力损伤,因此有可能成为早期监测新生儿及高危儿听力的一种方法。     

耳声发射应用于新生儿听力筛选的研究

目的 研究瞬态诱发耳声发射（ｔｒａｎｓｉｅｎｔ ｅｖｏｋｅｄ ｏｔｏａｃｏｕｓｔｉｃ ｅｍｉｓｓｉｏｎｓ，ＴＥＯＡＥ）产畸变产物耳声发射（ｄｉｓｔｏｒｔｉｏｎ ｐｒｏｄｕｃｔ ｏｔｏａｃｏｕｓｔｉｃ ｅｍｉｓｓｉｏｎｓ，ＤＰＯＡＥ）应用于新生儿听力筛选的可行性，控诉听力筛选的标准。方法 应用Ｃｅｌｅｓｔａ５０３型耳声发射分析仪对１０８名新生儿（２１６耳）进行ＴＥＯＡＥ和ＤＰＯＡＥ听力筛选，与听性脑     

正常新生儿短声诱发性耳声发射

正常新生儿短声诱发性耳声发射ＭＲＫｏｋＧＡｖａｎＺａｎｔｅｎＭＰＢｒｏｃａａｒｅｔａｌ．本文研究的目的：（１）应用诱发性耳声发射（ＥＯＡＥ）进行新生儿听力筛选的可行性；（２）新生儿ＥＯＡＥ的基本特征，并与成人者进行比较；（３）确定大群体正常新生儿ＥＯ...     

Assessment of the medial olivocochlear efferent system in children. pure tone 1.0 kHz and 2.0 kHz suppressive effects on transient evoked otoacoustic emission

The role of medial efferent system in regulating outer hair cell function has been studied by many investigators. Usually narrow band noise or white noise as contralateral stimulation (CS) suppressors have been used and changes in OAE amplitudes estimated. Thirty children aged 6-15 years (mean 12.5 +/- 4.7), without any changes in tonal and impedance audiometry and with negative history regarding otiatric diseases were examined. Transient evoked otoacoustic emissions (TEOAE) were recorded using ILO 92 Otodynamics Analyser. CS was performed using 1.0 kHz and 2.0 kHz continuous pure tones of 30 dB SL or 50 dB SL. Effects of CS on TEOAE evoked by click of 80, 70 and 60 dB SPL were investigated. TEOAE analysis included assessment of TEOAE amplitude of half octave frequency bandwidth (HOFBW-1.0; HOFBW-1.5; HOFBW-2.0; HOFBW-3.0 and HOFBW-4.0 kHz) and 0.8 kHz frequency bandwidth (0.8-FBW) amplitudes centred at 1.0; 2.0; 3.0; 4.0 and 5.0 kHz. TEOAE amplitude recorded for stimuli 80, 70 and 60 dB SPL without CS decreased: mean values respectively 6.1 +/- 4.2; 5.4 +/- 4.5 and 3.3 dB SPL +/- 4.3. CS effect on TEOAE was observed for all CS options, however, larger suppressive effect was recorded on TEOAE elicited by 70 dB SPL stimulus using 1 kHz/50 dB SL tone as a suppressor and on TEOAE elicited by 60 dB SPL stimulus using 2 kHz/50 dB SL tone as a suppressor. HOFBW and 0.8-FBW analyses showed the association between the frequency/intensity of the suppressors and decreasing of amplitudes of adequate frequency bands. It is concluded that the described method of investigating of the medial olivocochlear efferent system seems to be sensitive and confirms frequency-dependent suppressive effect on OAE.     

Otoacoustic emission examinations in soldiers before and after shooting

Firearms are a common source of impulse noise that may potentially damage hearing organ. The purpose of this study was evaluation of the click evoked otoacoustic emission (TEOAE) and distortion-product otoacoustic emission (DPOAE) before and after shooting and comparison with conventional pure tone audiometry. Standard pure tone audiometry, tympanometry, TEOAE and DPOAE were made before and 10-15 minutes after shooting. Ten male soldiers (20 ears) were exposed to impulse noise from automatic gunfire (15 single rounds of live ammunition). They did not use any earplugs. The reduction amplitude of the TEOAE after shooting was found especially for the frequency 3,4 kHz for the right ear and 1 and 2 kHz for the left ear. The DPOAE greatest reduction concerned frequency 2,5 and 4 kHz for the left ear. All our shooters were right-handed and probably the asymmetrical effect resulted from the shooting posture. Any differences existing between the audiometric threshold before and after shooting were not noticed. Clinical experience with OAE indicates that it may play a role as a screening method for the soldiers exposed to noise and as a tool for monitoring early changes in cochlea. Emissions seem to be more sensitive for monitoring early cochlear changes after shooting than pure tone audiometry.     

Normative auditory brainstem response data for hearing threshold in the rabbit

In an experimental study, we determined the physiological hearing threshold of the rabbit in order to use these data as normative values for further experimental investigations. The aim was to use different acoustic stimuli (click and tone-pip stimuli) with different frequency spectra for air and bone conduction (BC) in order to obtain further information about the optimal form of stimulus when recording auditory evoked potentials in the rabbit. For the investigation, we used 46 female New Zealand rabbits weighing 3.2-4.4 kg and aged 6 months. The equipment used to record brainstem auditory evoked potentials was the Nicolet Viking IV P System (Nicolet Biomedical, Inc.). In accordance with the experimental set-up, the measurements took place under intubation anesthesia, with a total of four repeat measurements performed on each ear at different times. Tone-pip and click stimuli with varying intensities of stimulus, transmitted via air conduction and BC, were applied. The I-IV waves proved the most stable for both stimulus modalities. They were registrable in 98.7% of cases, whereas only 30.2% of the V waves could be recorded. Values averaged from all measurements made throughout the study yielded a potential threshold of 34.8 dB peak equivalent (p.e.) SPL for the click stimulus, 13.8 dB p.e. SPL for the tone-pip stimulus at 8 kHz and 34.2 dB p.e. SPL for the click stimulus transmitted via BC. With regard to latencies, the results indicated a good reproducibility through different stimuli with acceptable standard deviations. The values for physiological hearing threshold obtained here can serve as normative data in subsequent experimental animal studies.     

Digital subtraction method for transient evoked otoacoustic emission recording with ipsilateral noise suppression: an application to stimulus artifact reduction.

The suppression of transient evoked otoacoustic emissions (TEOAEs) by continuous ipsilateral noise masking was investigated to explore the feasibility of its use in the elimination of the acoustical stimulus artifact. A reference noise template was obtained by stimulating the ear with identically reproducible digitally synthesized broadband noise. The same noise was used to suppress a TEOAE generated by an ipsilaterally presented click under the same conditions. Digital subtraction of the reference noise from the noise-suppressed TEOAE resulted in obtaining a template of a click artifact for that ear. The results have shown that the digital subtraction method cancels the suppressor noise, enabling the observation of the suppressed TEOAE. The subtraction of the stimulus artifact template from the original TEOAE allowed the recovery of the emission waveform with substantially reduced stimulus artifact, thus enabling the recovery of high-frequency otoacoustic emission components.     

Influence of static middle ear pressure on transiently evoked otoacoustic emissions and distortion products

Otoacoustic emissions (OAE) are influenced in their amplitude and frequency spectra by the middle ear. The effects of changes in the middle ear transmission mechanisms on transiently evoked OAE (TEOAE) and distortion product emissions (DPOAE) were investigated as a function of static ear canal pressure in 25 normal-hearing test persons aged 18–35 years. The ear canal pressure was varied stepwise between positive and negative values of 200 daPa. TEOAE and DPOAE amplitudes were attenuated significantly with changes of the static ear canal pressure, with greatest changes at low frequencies (< 2 kHz). The alterations of OAE amplitude were slightly dependent on the polarity of the pressure, with positive pressure producing a greater attenuation (0.6 dB). The results demonstrate that changes in middle ear impedance can cause a misinterpretation of OAE. To avoid this problem, tympanometry should always precede OAE measurements. Alternatively, both methods can be combined using one acoustic probe, so that the emissions can be evoked at the peak of middle ear compliance.     

Acoustic modulation of electrically evoked otoacoustic emission in chickens

Electrically evoked otoacoustic emissions (EEOAEs) can be elicited from the chicken inner ear. Since lesion studies implicate hair cells are the source of EEOAEs, we hypothesized that acoustic stimuli would modulate EEOAE amplitude at cochlear locations where the acoustic and electrical stimuli overlap. To assess this interaction, EEOAEs were measured as the frequency and amplitude of the acoustic stimuli were varied. EEOAEs, evoked by AC current (3-250 microA rms) delivered to the round window had a broad band pass response (1-6 kHz) with a peak between 3 and 4 kHz and maximum amplitude of 27 dB SPL. EEOAE suppression/enhancement tuning curves were measured at 2, 3, 4 and 6 kHz by varying the frequency of a 70 dB SPL tone and measuring the change in EEOAE amplitude. EEOAE tuning curves were characterized by a tip; a narrow range of frequencies where EEOAE amplitude was suppressed by as much as 5 dB, and by sidebands, a range of frequencies above and below the tip where EEOAE amplitude was enhanced by as much as 1.5 dB. The best suppression frequency, or characteristic frequency, was close to the frequency of the EEOAE elicited by the 3- or 4-kHz electric stimulus. However, the characteristic frequency was displaced towards higher frequencies for the 2-kHz electric stimulus, and towards lower frequencies for the 6-kHz electric stimulus. EEOAE suppression increased approximately linearly with acoustic level. These results suggest that EEOAEs evoked by round window stimulation are predominantly generated by hair cells near the 3- to 4-kHz region of the cochlea.     

TEOAE-based estimation of the auditory threshold in the mid-octave frequencies

The purpose of this study was to estimate the hearing levels, at the mid-frequencies, of 233 ears with sensorineural hearing loss by classifying the corresponding transiently evoked otoacoustic emissions (TEOAE) recordings into three threshold groups. A classification algorithm was based upon a discriminant analysis of fast Fourier transform (FFT) data, evoked by non-linear click stimuli of 80 (+/-2) dB SPL per ear. To validate the efficiency of the proposed methodology TEOAE recordings were initially grouped by mean hearing level values of the 1 kHz and 2 kHz octaves into three threshold ranges according to two strategy schemes: in the first, TEOAE data were assigned into 10-19 dB HL, 20-39 dB HL or > or = 40 dB HL groups. In the second, TEOAE data were assigned into 10-29 > dB H >, 30-39 dB HL or > or = 40 dB HL groups. The most accurate prediction estimates were obtained from the second strategy scheme with a 90.9% accuracy in the 10-29 dB HL group, 82% in the 30-39 dB HL group and 71.4% in the > or = 40 dB HL group.     

新生儿与成人瞬态诱发耳声发射差异的频谱特性分析

目的 比较新生儿与成人瞬态诱发耳声发射(TEOAE)的差异,并分析其频谱特性.方法 以短声刺激分别对120名通过听力筛查的新生儿(男58,女62)和32名平均纯音听阈(听力级)在20 dB以内的成年人(男15,女17)行TEOAE检测,对于测试结果 行频谱分析和半倍频程分析.结果 ①新生儿组TEOAE总强度(声压级,下同)为(15.18±4.39)dB,高于成人组的(9.51±4.12)dB,差异具有统计学意义(t=9.303,P<0.05).②新生儿的频带重复率、频带重复率非0比例、频带信噪比检出率及频带信噪比在第1频带(0.8 kHz)最低,在3.2 kHz最大;而成人在第5频带(4.0 kHz)处最低,在1.5 kHz最大.③新生儿与成人最大频带信噪比强度差为7.09 dB,二者出现的频率位置相差约1.7 kHz.④半倍频程分析显示新生儿TEOAE最大能量为(10.50±5.09)dB,在2828 Hz处,而成人为(2.84±5.33)dB,在1414 Hz处;二者最大反应在强度上相差7.66 dB,出现的频率位置相差1414 Hz.⑤成人1.5 kHz区的TEOAE信号最强,之后其信噪比随频带增高而降低,而新生儿信噪比却呈现随频带增高而增强的特征;从第1频带到第5频带,新生儿与成人TEOAE强度的差值随频带增高也逐渐增大.结论 成人TEOAE总强度低于新生儿.新生儿频带信噪比及半倍频程能量反应峰的分布频率及反应强度均高于成人.     

Development of auditory asymmetry in transient evoked otoacoustic emissions in pre-term infants

We previously reported that transient evoked otoacoustic emissions (TEOAEs) continue to develop after the onset of cochlear function in pre-term infants from 34 to 39 weeks of conceptional age (Morlet et al., 1996). The time-course of development differed between genders. Reported here are findings of further analysis of data from the study cohort, comprising 1020 ears of 510 pre-term neonates (conceptional age ranging from 34 to 39 weeks), demonstrating developmental differences between right and left ears. The left ear of female pre-term infants showed enhancement of TEOAE amplitude at low and medium frequencies with age, whereas differences were less dramatic in the right ear. In male infants, TEOAE amplitude decreased in several frequency bands at high frequencies, above 4 kHz, between 34 and 39 weeks conceptional age; most developmental differences were found to be more dramatic in the right than in the left ear. It is tempting to speculate that these developmental features underlie well-known inter-aural asymmetries that have been demonstrated in the adult human.     

Intra- and intersubject variability of acoustically evoked otoacoustic emissions. I. Transiently evoked otoacoustic emissions]

BACKGROUND: Acoustically evoked otoacoustic emissions are becoming increasingly significant in the clinical monitoring of cochlear function in adults. Any interpretation of these measurements in a clinical setting must consider their intra- and intersubject variability. METHODS: Transiently evoked otoacoustic emission (TEOAE) measurements were performed in 32 normally hearing adults in three weekly test sessions. Each ear was tested twice per session, and the results were statistically analyzed. RESULTS: All test candidates had measurable TEOAEs. Statistically significant differences in TEOAE amplitudes were neither found between two measurements at the same day, nor at weekly intervals. No statistically significant amplitude differences were found between right and left ear of the same candidate. TEOAE amplitudes in women were always higher than in men with statistically significant differences in the 2, 3, and 4 kHz frequency band. CONCLUSIONS: These results indicate that monitoring of the inner ear status can be reliably performed using TEOAE measurements. Changes in TEOAE amplitudes effectively indicate changes in the cochlear function.