Transient evoked otoacoustic emissions in patients with middle ear disorders

The aim of this study is to investigate the middle ear dynamic characteristics and their influence on TEOAEs in patients with middle ear disorders. The middle ear dynamic characteristics and TEOAE findings were investigated in 89 patients with middle ear disorders using the sweep frequency impedance (SFI) meter and the ILO88 system, respectively. These patients were divided into six subcategories: tympanic membrane aberrations, otitis media with effusion, chronic otitis media, tympanic membrane perforation, otosclerosis, and ossicular chain dislocation. Details of the TEOAE frequency characteristics were compared with the individual's middle ear dynamic characteristics. TEOAE status as a function of hearing threshold and middle ear dynamic characteristics was also examined. The results showed that the middle ear dynamic characteristics in patients with middle ear disorders correlated with the TEOAE frequency characteristics and amplitudes. The hearing level and middle ear mobility were the controlling factors affecting TEOAE status. Using both non-linear and linear stimulus modes, larger TEOAE responses were obtained when the hearing level was better than 20 dB HL, and there was moderately good middle ear mobility. Moreover, TEOAEs were absent using the non-linear mode when the hearing level was worse than 30 dB HL, whereas with the linear mode. TEOAEs were recordable even with hearing losses of up to 40 dB HL in patients with middle ear disorders. A higher incidence of recordable TEOAEs was found in the subgroups with tympanic membrane abnormalities and secretory otitis media when compared with the other subgroups. No TEOAEs were recordable in patients with chronic otitis media.     

婴幼儿宽频声导抗测试

婴幼儿外中耳解剖和功能上的特殊性,使得传统的单频声导抗测试评估婴幼儿中耳功能有一定的局限性。宽频声导抗测试可以在宽频(0.2~8 kHz)范围内评估声能的接收与传递,与传统单频声导抗相比,不需要对外耳道加压,测试时间短,可以动态评估新生儿及婴幼儿外周听觉发育特性及中耳功能。应用宽频声导抗测试可以提高婴幼儿听力筛查结果和中耳功能评估的准确性。     

Sweep frequency impedance measures in young infants: developmental characteristics from birth to 6 months

Objective: International Journal of Audiology To study the developmental characteristics of sweep frequency impedance (SFI) measures in healthy infants from birth to 6 months. Design: All infants were assessed using high-frequency tympanometry (HFT), distortion product otoacoustic emission (DPOAE) and SFI tests. SFI measures consisted of measurement of resonance frequency (RF) and mobility (ΔSPL) of the outer and middle ear. A mixed model analysis of variance was applied to the SFI data to examine the effect of age on RF and ΔSPL. Study sample: Study included 117 ears from 83 infants of different age groups from birth to 6 months. Results: The mean RF of the outer ear increased from 279?Hz at birth to 545?Hz at 4 months, whereas mean ΔSPL of the outer ear decreased from 7.9?dB at birth to 3.7?dB at 4 months of age. In contrast, the mean RF and ΔSPL of the middle ear did not change significantly with age up to 6 months. Conclusions: Developmental characteristics should be considered when evaluating the function of the outer and middle ear of young infants (≤6 months) using the SFI. The preliminary normative SFI data established in this study may be used to assist with the evaluation.     

Multifrequency tympanometry: experimental application after implantation of ossicular replacement prosthesis in rabbits.

HYPOTHESIS: We used multiple-frequency tympanometry (MFT) to evaluate the influence of a newly developed ossicular replacement prosthesis on transmission characteristics of middle ear. BACKGROUND: Multiple-frequency tympanometry is a technique for evaluating the emittance of the middle ear over a wide frequency range. It has been shown to be sensitive to certain middle ear conditions that are not detected by conventional 226-Hz tympanometry. In the field of experimental evaluation, MFT has been shown in certain animal studies to be useful in monitoring diseases. METHODS: Thirty-six prostheses composed of titanium dioxide ceramic were implanted into the right middle ear of female rabbits. Bilateral measurements using conventional 226-Hz and MFT were performed before implantation and after 28, 84, and 300 days postoperatively. The results of the preoperative examinations yielded reference values for physiological resonance frequency. After dissecting the temporal bone, we opened the middle ear and analyzed both the surrounding tissue and the position of the prosthesis. RESULTS: The constant values for compliance revealed by both preoperative and postoperative measurements indicate good reproducibility of 226-Hz tympanometry. Postoperatively, resonance frequency increased continuously up to the 300th day. The observation supports the assumption that the higher stiffness level of connective tissue influenced resonance frequency. CONCLUSION: The reference values in this study can serve as guidelines for further experimental trials.     

Analysis of the resonant frequency of the middle ear in otosclerosis

Multifrequency tympanometry scans pressures and frequencies from 226 to 2000 Hz to analyze the resonant frequency of the middle ear, which determines the balance between stiffness and mass. We studied 143 patients (a total of 200 ears) diagnosed as otosclerosis at the E.N.T. Service of Santiago de Compostela University Hospital Complex, and 136 control subjects. The mean age of patients was 47.7 years; women were predominant (female/male ratio 2.25:1). The mean duration of the disease was 10.4 years. Using the Virtual model 310 tympanometer, we calculated the resonant frequency through the susceptance tympanogram, corresponding to the minimal frequency at which the central notch of the tympanograrn was equal to or less than the negative tail. The mean resonant frequency was 1230 Hz, the tympanometric amplitude was 88.32 daPa, and the admittance of the middle ear was 0.63 cc. We confirmed an increase in the resonant frequency in patients with otosclerosis compared with normal subjects (1132.33 Hz), and a decrease in the admittance of the middle ear. The relation between the two values was significant.     

Results of multiple-frequency tympanometry measures in normal and otosclerotic middle ears

Tympanometry is a non-invasive, quick, and inexpensive method for examining the middle-ear function. Its limited value in differentiating otosclerotic from normal middle ears caused researchers to develop new methods for evaluation of middle ears. Resonant frequency had been found to be higher in otosclerotic middle ears than normals. We conducted multiple-frequency tympanometry measurements in 25 surgically confirmed otosclerotic ears and 100 normal ears. Mean middle-ear resonant frequency for the otosclerotic group was found to be 1190 Hz and mean middle-ear resonant frequency of the control group was 934.6 Hz (p<0.001). With a cut off value of 1025 Hz (based on 95% confidence interval), sensitivity was 80% and specificity was 82%. The present findings confirm the advantage of the resonant frequency estimation over conventional tympanometry in detecting middle-ear status and mechanics in patients with otosclerosis. As a conclusion, detecting resonant frequency when evaluating patients for otosclerosis must be an essential part of examination. Nevertheless, further investigation is necessary for better diagnosis of otosclerosis preoperatively.     

Results of multiple-frequency tympanometry measures in normal and otosclerotic middle ears

Tympanometry is a non-invasive, quick, and inexpensive method for examining the middle-ear function. Its limited value in differentiating otosclerotic from normal middle ears caused researchers to develop new methods for evaluation of middle ears. Resonant frequency had been found to be higher in otosclerotic middle ears than normals. We conducted multiple-frequency tympanometry measurements in 25 surgically confirmed otosclerotic ears and 100 normal ears. Mean middle-ear resonant frequency for the otosclerotic group was found to be 1190 Hz and mean middle-ear resonant frequency of the control group was 934.6 Hz (p<0.001). With a cut off value of 1025 Hz (based on 95% confidence interval), sensitivity was 80% and specificity was 82%. The present findings confirm the advantage of the resonant frequency estimation over conventional tympanometry in detecting middle-ear status and mechanics in patients with otosclerosis. As a conclusion, detecting resonant frequency when evaluating patients for otosclerosis must be an essential part of examination. Nevertheless, further investigation is necessary for better diagnosis of otosclerosis preoperatively.     

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。     

The change in the acoustic admittance phase angle: a study in children suffering from acute otitis media

Middle ear mechanics, in normal and in pathological conditions, is the subject of this research, with acoustic impedance measurements as the cornerstone. Previous studies have established the importance of admittance-phase tympanograms, mainly in frequencies higher than the conventional 226 Hz. The purpose of the present study was to record how acute otitis media (AOM) affects the middle ear system and function by evaluating the recordings of the change in phase angle parameter (deltatheta) provided by an automated tympanometer using the sweep-frequency technique. Multifrequency and conventional tympanograms were obtained from 70 children suffering from AOM on consecutive visits. Values of deltatheta from these subjects were compared to normative data previously acquired in our Department. It appears that changes in the mechanical status of the middle ear after AOM are reflected in abnormal deltatheta values, despite the normal findings of conventional tympanometry. A positive history of AOM did not seem to influence the behaviour of the middle ear. In most cases, abnormal deltatheta values coexisted with abnormal values of resonance frequency (RF), i.e. the frequency at which mass and stiffness of the middle ear are in balance, and total susceptance (deltaB) reaches 0mmhos and the converse. The deltatheta seems to be an important indicator of middle ear mechanical status that can record changes occurring in the system after AOM and undetected by low probe-tone tympanometry.     

中耳共振频率对鼓室积液的诊断价值

目的:探讨226 Hz静态鼓室图与中耳共振频率诊断鼓室积液的价值,观察两者结合可否提高诊断效能.方法:前瞻性研究对比观察分泌性中耳炎组和对照组,以耳镜检查、纯音测听及GSI-33型中耳分析仪测试结果为标准,将对照组共振频率90%的可信区间(5%～95%)设为正常范围,对分泌性中耳炎组的共振频率进行正常或不正常归类,并对其鼓室图形为B、C型或异型者进行鼓膜穿刺抽液,以抽出液体者为阳性.结果:中耳共振频率在900～1100 Hz之间为正常,分泌性中耳炎组的共振频率明显低于对照组(P＜0.01).B型曲线的抽液阳性率为83%,明显高于C型和异型曲线抽液阳性率(P＜0.05).共振频率正常者,其抽液阳性率为0.≤500 Hz者的鼓室积液阳性率明显高于＞500 Hz者(P＜0.01).结论:通过测试中耳共振频率对判断鼓室是否积液,尤其是对鼓室图形为C型或异型者有重要临床意义.     

Parameters of normality in multifrequency tympanometry

Multifrequency tympanometry studies consist of tympanography using probe tone frequencies ranging from 200 to 2000 Hz, improving the study of acoustic transmission through the tympano-ossicular system because then two components of admittance, conductance and susceptance, can be separated. The resonance frequency is the frequency at which mass and spring elements of the middle ear cancel each other out, leaving only the friction component. This measurement has been found to be more sensitive to the presence of pathologies that affect the tympano-ossicular system, such as otosclerosis and rheumatoid arthritis. It is necessary to know normal pattents of tympanometric parameters to improve the study of these diseases. Multifrequency tympanometry performed on 136 patients, 91 women and 45 men, age range 11-78 years. The mean resonant frequency of the middle ear was 1132.33 Hz, mean static admittance 0.76 dapa, and mean tympanometric amplitude 94.31 mmhos ac. Age showed no systematic effect of age on any of these measures in this population, and no significant association was found between static admittance or tympanometric amplitude and resonance frequency.     

Distinguishing healthy from otosclerotic ears: effect of probe-tone frequency on static immittance

The diagnostic utility of static immittance (SI) with respect to distinguishing healthy from otosclerotic ears was investigated at different probe-tone frequencies in 68 healthy ears and 36 ears with surgically confirmed otosclerosis. Because one effect of otosclerosis is to shift the resonant frequency of the middle ear to higher values as a result of increased stiffness of the middle ear system, it was hypothesized that SI measured at higher probe-tone frequencies may provide a better distinction between healthy and otosclerotic ears. As expected, the results of this study indicate that SI measured at higher probe-tone frequencies is superior to a standard low probe tone in the detection of otosclerotic ears. Through systematic and objective comparisons of relevant probetone frequencies using both group statistics and test performance analysis, the present study suggests 630 Hz as an optimum probe-tone frequency for measuring SI with respect to distinguishing healthy ears from otosclerotic ears.     

Effects of ear canal static pressure on the dynamic behaviour of outer and middle ear in newborns

ObjectiveThe present study investigated the effect of ear canal pressure on the dynamic behaviour of the outer and middle ear in newborns with and without a conductive condition using the sweep frequency impedance (SFI) technology.MethodsA test battery consisting of automated auditory brainstem response (AABR), transient evoked otoacoustic emission (TEOAE) and 1000-Hz tympanometry (HFT) was performed on 122 ears of 86 healthy newborns and 10 ears of 10 newborns with a conductive condition (failed TEOAE and HFT). The dynamic behaviour of the outer and middle ear, when the pressure applied to the ear canal was varied from 200 to −200 daPa, was evaluated in terms of the sound pressure level (SPL) in the ear canal, resonance frequency (RF) and displacement (ΔSPL).ResultsApplication of either a positive or negative static pressure to the ear canal of healthy newborns increased the resonance frequency of the outer (RF1) and middle ear (RF2), but decreased the displacements of the outer (ΔSPL1) and middle ear (ΔSPL2). Positive static pressures resulted in lower SPL while negative static pressures resulted in higher SPL than that at ambient pressure (0 daPa). At −200 daPa, more than 90% of ears showed signs of collapsed ear canal. The dynamic behaviour under various positive and negative static pressures for newborn ears with a conductive condition indicated similar pattern of SPL, RF1 and ΔSPL1 responses for the outer ear as per healthy ears, but abnormal responses for the middle ear.ConclusionsWhile both positive and negative pressures applied to the ear canal have the same effect of stiffening the outer and middle ear, negative pressure of up to −200 daPa resulted in more than 90% of ears with a collapsed ear canal. The results of the present study do not only offer useful clinical information for differentiating healthy ears from ears with a conductive condition, but also provide information on the maturation aspects of the outer and middle ear in newborns.     

Prognostic value of multiple-frequency tympanometry in acute otitis media.

Multiple-frequency tympanometry (MFT) and conventional 226-Hz tympanometry were performed in 86 ears of children affected by acute otitis media (AOM) after therapy. In a 3-month follow-up period, the recurrence rate of AOM and persistence of middle-ear effusion in these children were evaluated in comparison with the early results of the two methods, as well as the relation of MFT findings to the possibility of development of AOM sequelae. It seems that abnormal resonant frequency values and recordings by MFT right after an episode of AOM indicate persistence of changes in the mass and stiffness balance of the middle ear, not demonstrated by conventional tympanometry, that could be responsible for a higher probability of AOM sequelae.     

Unfavourable prognostic factors in patients treated surgically for otosclerosis

Abstract

Backgrounds: Otosclerosis is the cause of between 5% and 9% of all deafness cases and between 18% and 22% of conductive hearing loss cases. Neurosensory deafness develops in 30% of patients with otosclerosis.

Aims/Objectives: The aim was to seek a correlation that would reflect the dependence of the results of middle ear surgery on the type of abnormalities atypical of otosclerosis but found during the stapedotomy surgery.

Materials and Methods: The analysis included 140 patients who underwent surgery for otosclerosis. The hearing of all patients was assessed using an audiometric test.

Results: In the assessment of changes in the mean bone conduction values, statistically significant differences between the reference group and the subgroup of patients on whom a myringoplasty was performed, as well as in patients with adhesions present in the middle ear spaces, were found only for the 500?Hz frequency.

Conclusion and Significance: The removal of abnormalities, such as the loss of the eardrum (iatrogenic), changes to the lining and adhesions other than those typical of otosclerosis, restores middle ear mechanics after a stapedotomy on the inner ear and leads to a measurable improvement in mean bone conduction values.     

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.     

Standard and multifrequency tympanometric norms for Caucasian and Chinese young adults

OBJECTIVE: This study examined differences between a group of normal-hearing Caucasian and Chinese young adults on six tympanometric parameters. The goal of this study was to determine if the Chinese group had different low and multifrequency tympanometry results than the Caucasian group. DESIGN: There were a total of 159 subjects (303 ears) between the ages of 18 and 34 years, with 76 subjects in the Caucasian group and 83 subjects in the Chinese group. Tympanometric data were gathered on a clinical immittance machine, the Virtual 310 equipped with a high frequency option. Four of the parameters-static admittance (SA), tympanometric width (TW), tympanometric peak pressure (TPP), and ear-canal volume (ECV)-were measured automatically at a standard 226 Hz frequency. The remaining two parameters-resonant frequency (RF) and SA up to 1,200 Hz-were measured by multifrequency, multicomponent tympanometry, using a mathematical approach. RESULTS: The Chinese group had significantly lower SA, wider TW, more positive TPP, and lower ECV than their Caucasian counterparts. The parameter of SA up to 1,200 Hz showed a significant group effect (Caucasian versus Chinese) until 900 Hz in the male group and up to 1,120 Hz in the female group. The Chinese group had significantly higher RF than the Caucasian group. Once the effect of body size was compensated by adjusting for the ear canal and the middle ear volumes, the differences observed between the Caucasian and the Chinese groups were no longer significant for tympanometric parameters obtained at standard probe tone frequency of 226 Hz; however, the effect was still significant for SA obtained at higher probe tone frequencies (560, 630, 710, 800, and 900 Hz) and for RF. Applying the Caucasian norms to a group of mainly Caucasian adults with surgically confirmed otosclerosis resulted in improved overall test performance when compared with the combined Caucasian and Chinese norms and the Chinese only norms. CONCLUSIONS: It seems that the body size plays a crucial factor in the observed differences between the Caucasian group and Chinese groups at a standard probe tone frequency of 226 Hz; however, other mechano-acoustical properties of the middle ear may contribute to these differences at higher probe tone frequencies. Findings of this study suggest that further research is needed to investigate the effects of body size on immittance measures with other ethnic groups. In the meantime, overall test performance may be improved by using a more homogenous norm when testing the Caucasian or Chinese individuals.     

The doubtful value of tympanometry in the diagnosis of otosclerosis

Many consider that the compliance of the middle ear as measured from the tympanogram can be helpful in diagnosing otosclerosis. To test this assertion, the compliance in 34 individuals with surgically proven otosclerosis was compared with the compliance in 34 age and sex matched, normal controls, randomly selected from the population. Though the mean compliance was different in the two groups, there was considerable overlap in the range of values which severely limits the practical usefulness of tympanometry. If the level of compliance is taken at which a false negative diagnosis would be made in 10 per cent of otosclerotic ears, a false positive diagnosis of otosclerosis would be made in 88 per cent of normal ears. If the level of compliance is taken at which a false positive diagnosis of otosclerosis would be made in 10 per cent of normal ears, 72 per cent of ears with otosclerosis would be considered normal. It is concluded that tympanometry will not help to arrive at a diagnosis of otosclerosis.     

An assessment of the validity of tympanometry compared to myringotomy performed under a nitrous oxide-free general anaesthetic

To assess the validity of tympanometry as a test for the presence of middle ear effusion using a ‘gold-standard’ of myringotomy performed after a nitrous oxide-free general anaesthetic, we performed a prospective validity study comparing tympanometry traces obtained immediately pre-operatively from patients undergoing grommet insertion, with the otomicroscopic findings at myringotomy. Nitrous oxide was omitted from the anaesthetic gaseous mixture as it has been reported to displace middle ear effusions. One hundred and seventy-two patients (aged 1.5–15 years) with a clinically assessed 3 month history of middle ear effusion were included in the study. Sensitivity and specificity of a Jerger classification Type B tympanometric trace for the presence of middle ear effusion were 0.73 and 0.84, respectively. We conclude that tympanometry is a valid test in assessing the presence of middle ear effusion compared to a ‘gold standard’ of myringotomy performed after a nitrous oxide-free general anaesthetic.     

Tympanometry and laser Doppler interferometry measurements on otitis media with effusion model in human temporal bones.

HYPOTHESIS: The aim of this study is to investigate the effect of middle ear fluid and pressure on tympanic membrane mobility by using laser Doppler interferometry and to compare these results with tympanometry. BACKGROUND: Tympanometry has been commonly used for evaluation of otitis media with effusion, a middle ear disease with fluid in the cavity. However, this test lacks specific interpretations of middle ear disorders based on tympanometric data. Laser interferometry, as an advanced research tool to measure middle ear function, may provide knowledge of how tympanic membrane mobility is affected by middle ear fluid and pressure. METHODS: An otitis media with effusion model was created in seven human temporal bones for conducting experiments with tympanometry and laser interferometry. Middle ear pressure varied from -20 to +20 cm water, and the amount of fluid in the middle ear was gradually increased to fill the cavity. RESULTS: The displacement of the tympanic membrane measured by laser interferometry at selected frequencies decreased significantly corresponding to the middle ear air pressure changes. Tympanometry detected middle ear pressure by the change of tympanometric peak location, but the tympanogram shape was not affected by the middle ear pressure. The middle ear fluid was detected by tympanometry with as little as 0.3 mL, and laser interferometry was able to measure the displacement change of the tympanic membrane with 0.2 or 0.3 mL fluid at different frequencies. CONCLUSION: Laser interferometry can detect the effect of middle ear pressure and fluid on tympanic membrane movement as well as tympanometry does.