Comparison of sonotubometry, impedance, tubo-tympano-aerography, and tubomanometry to test eustachian tube function.

PURPOSE: There is currently no gold standard for the diagnosis of eustachian tube (ET) dysfunction. To provide an objective basis for the clinical diagnosis of ET dysfunction, we explored the characteristics of sonotubometry, impedance, tubo-tympano-aerography (TTAG), and tubomanometry (TMM) in volunteers with healthy ETs. MATERIALS AND METHODS: Sonotubometry, impedance, TTAG, and TMM tests were performed in 110 healthy ears of 55 volunteers, and the characteristics of each ET test were compared and discussed. RESULTS: The ET opening rate was compared between sonotubometry with dry swallowing, impedance with the Valsalva maneuver, TTAG with the Valsalva maneuver, and TMM with a nasopharyngeal pressure of 50 mbar in 100 (90.9%), 102 (92.7%), 99 (90.0%), and 104 (94.5%) ears, respectively; there was no significant difference among the four methods (P = 0.575). In sonotubometry, both dry swallowing and the Valsalva maneuver were superior to wet swallowing in terms of detecting ET opening (P = 0.000). In TMM, both the opening rate and the external auditory canal pressure were positively correlated with the nasopharyngeal pressure. Specifically, the opening rate and external auditory canal pressure increased with an increase in the nasopharyngeal pressure (r = 0.271, P = 0.000; r = 0.315, P = 0.000, respectively). CONCLUSIONS: Sonotubometry, impedance, TTAG, and TMM have their own advantages and disadvantages. In clinical practice, the appropriate ET function test should be chosen on the basis of the patient's specific condition.

A manual of Eustachian tube function tests-illustration of representative test results obtained from healthy subjects and typical disorders with suggestion of the appropriate test method of choice.

In the 19th century, Politzer devised a method to measure passage of the Eustachian tube (ET) by pressurizing the nasopharyngeal cavity, which marked the beginning of the ET function test. Since then, various examination methods have been developed. While ET function testing is important, recent advancements in diagnostic imaging and treatments have renewed interest on its importance. In Japan, the main objective methods used for examining ET function include tubotympanoaero-dynamic graphy (TTAG), sonotubometry, and the inflation-deflation test. The Japan Otological Society (JOS) Eustachian Tube Committee has proposed a manual of ET function tests, which presents typical patterns of the normal ear and typical diseases and suggests the ET function test of choice for each disease. However, the diagnosis of each disease should be made based on a comprehensive history and various examination findings, with ET function tests playing a supplemental role in the diagnosis.

Eustachian Tube Dysfunction Diagnostic Pathway-What Is the Current State of the Art and How Relevant Is Chronic Nasal Disease?

Background: Eustachian tube dysfunction (ETD) presents a complex diagnostic challenge in otolaryngology, compounded by its multifaceted nature and overlapping symptoms with chronic nasal disease. This article examines the intricacies of ETD diagnosis, emphasising the necessity for a consensus on diagnostic procedures. Methods: A review of the literature was performed through the OVID research tool in the Pubmed/Medline databases to identify relevant articles that discuss eustachian tube dysfunction diagnostics as well as its correlation with chronic nasal disease. Results: The literature review harvested 201 articles, and only 51 of them were included in the full text review. A consensus statement was identified on eustachian tube dysfunction, function and diagnostics. It appears that there is significant variability in the diagnostic tools used to identify eustachian tube dysfunction. The main diagnostic approaches used are tympanometry, tubomanometry and sonotubometry, combined with the Patient-Reported Outcome Measure ETDQ-7 questionnaire to support the diagnosis of the condition. Nasal pathology is mostly absent from the retrieved studies, while ear pathology is more commonly mentioned in the current literature. Conclusions: There is no gold standard diagnostic tool to determine the presence of eustachian tube dysfunction. Further discussion, large multicentre studies and focused research are required to achieve a consensus on a diagnostic approach. The authors suggest a diagnostic pathway that combines subjective and objective diagnostic tools to determine the presence of eustachian tube dysfunction. This pathway is simple and can be used in district ENT departments, highlighting the nasal pathology relevance to ETD.

Sound and Noise Sources in Sonotubometry: An Investigation of Eustachian Tube Assessment.

This research aims to enhance the understanding of the acoustic processes occurring during sonotubometry, a method used to assess the Eustachian tube (ET) function. Recent advancements in digital signal processing enable a more comprehensive data analysis. In this project, a silicone model of the ET was developed to systematically study the existing noise and sound sources. These measurements were then compared with recordings from human subjects. Three distinct 'noise sources' were identified, which can influence the assessment of the ET opening using transmission measurements of the imposed signal: sound leakage from the speaker, a clicking noise at the initiation of ET opening, and rumbling/swallowing noise. Through spectral analysis, it was also possible to ascertain the spectral and temporal occurrence of these sound and noise types. The silicone model exhibited remarkable similarity to the healthy human ET, making it a robust experimental model for investigating the acoustics of sonotubometry. The findings underscore the significance of delving deeper into the analysed sound, as the noise occurring during sonotubometry can be easily misconstrued as an actual ET opening. Particularly, careful consideration is warranted when evaluating data involving clicking and swallowing noise.

Tympanic membrane findings and Eustachian tube function after transtympanic plugging for the chronic patulous Eustachian tube.

OBJECTIVE: To evaluate Eustachian tube (ET) function after Kobayashi plug surgery based on the tympanic membrane (TM) findings and active opening (AO) of the ET assessed with sonotubometry. SUBJECTS AND METHODS: A retrospective survey of medical records identified 74 ears of 66 patients with patulous ET (PET) received transtympanic insertion of the Kobayashi plug. Excluding the six ears (6 patients) with abnormal preoperative TM, sixty-eight ears of 60 patients were found to have normal TM preoperatively. Among these 68 ears, there were 51 ears in which sonotubometry was performed both before and after surgery to evaluate whether the AO of the ET was positive or not. RESULTS: Out of the 68 ears with normal preoperative TM, 52 ears (76.5%) were judged successful (sum of complete relief and significant improvement). The postoperative TM was normal in 41 ears (60.3%), while 27 ears (39.7%) had abnormal TM findings postoperatively. The success rate was 75.6% (31/41) in ears with normal postoperative TM, while it was 77.8% (21/27) in ears with abnormal TM. Success in maintaining normal postoperative TM was found in 45.6% (31/68) of the total ears treated. Out of the 51 ears in which sonotubometry was performed both before and after surgery, AO was preoperatively positive in 88.2% of the ears (45/51), while it was positive in 64.7% (33/51) postoperatively. In thirty-four ears with normal TM postoperatively, AO was positive in 24 ears (70.6%), while it was positive in 9 out of 17 ears (52.9%) with abnormal postoperative TM. The success rate was 70.6% (36/51) for the 51 ears in which AO was assessed both pre- and postoperatively, and it was 66.7% (22/33) in ears with positive AO postoperatively, while it was 77.8% (14/18) in ears without AO postoperatively. The incidence of ears either having normal postoperative TM or positive AO postoperatively was 84.3% (43/51). Abnormal postoperative TM findings without effectiveness were found in 8.8% (6/68). CONCLUSION: The obstructive dysfunction of the ET is a calculated risk but did not occur in most ears after plugging with the Kobayashi plug. Therefore, routine insertion of the VT at the same time as the initial surgery is not recommended for PET cases that are adequately followed up.

Comparison of Eustachian tube ventilation function between cleft palate and normal patients using sonotubometry.

OBJECTIVE: To compare Eustachian tube ventilation function between cleft palate subjects and normal subjects using sonotubometry. METHOD: A comparative cross-sectional study was conducted at the Department Otolaryngology-Head and Neck Surgery of Ciptomangunkusumo National Hospital, Universitas Indonesia, Jakarta, from June 2013 to January 2014.There were 31 subjects with cleft palate and 62 healthy subjects aged ≤18 years, and both groups were matched according to age. Each subject underwent ear, nose, and throat examination with Veau classification and sonotubometry, a new assembly test in Indonesia. The results of the sonotubogram (the number of Eustachian tube openings, amplitude enhancement in dB, and the duration of Eustachian tube opening in ms) were then analyzed with SPSS using chi-square and Mann-Whitney tests. RESULTS: Subjects with cleft palate had lower Eustachian tube function than healthy subjects using three sonotubometry parameters (p < 0.001). The proportion of Eustachian tube dysfunction based on the Veau classification was significant (p < 0.001). In multivariate analysis, several determinant factors of Eustachian tube dysfunction were found, such as adenoid hypertrophy (risk factor6.46), the number of Eustachian tube openings (risk factor 36.21), and higher Veau classification (risk factor 10.41). CONCLUSION: Sonotubometry could be used to assess parameters of Eustachian tube function. Subjects with cleft palate have a higher risk of having Eustachian tube dysfunction, as do subjects with adenoid hypertrophy.

Objective assessment of autophony during phonation in the diagnosis of patulous Eustachian tube patients.

OBJECTIVE: A system enabling the objective assessment of the transmission of voice sounds to the external auditory canal (EAC) during phonation has recently been revised. Our aim was to evaluate the effectiveness of this new system in the diagnosis of patulous Eustachian tube (PET) patients by comparing the results obtained using this method with those obtained from conventional objective tests to diagnose PET. METHODS: A prospective survey of medical records was included with definite PET, possible PET, and sensorineural hearing loss as control. The measurement system consists of a personal computer, an AD/DA converter (NI 6361, National Instruments), a probe microphone system for recording voice sound (ER-10C, Etymotic Research) and two microphones for measuring noise sound in the EAC (ER-10B+, Etymotic Research). Pronouncing the "Ni" sound for 5 s were recorded with these three microphones. The ratio of the maximum sound pressure of voice sound and noise sound in EAC (EAC/Voice) was simultaneously calculated, and results were displayed on a personal computer for diagnosing. RESULTS: Thirty-one patients of 42 ears with definite PET, 26 patients of 38 ears with possible PET, and 12 patients of 24 ears with sensorineural hearing loss as control were included. The EAC/Voice were 8.63 ± 5.43, 25.41 ± 32.63, and 25.87 ± 24.93 in the control, definite PET, and possible PET group respectively. The control group was significantly different from the definite PET (p < 0.05) and possible PET group (p < 0.05). ROC curve analysis confirmed 14.7 as the best diagnostic cut-off value of EAC/Voice (area under the curve=0.782, 95% CI 0.671-0.894). By adopting this cut-off point, 25 (56.8%) and 22 (61.1%) ears were determined as positive findings in the definite PET and possible PET group, respectively. There was no significant correlation between the positive findings judged by the current method and that of sonotubometry in the control (r = -0.63, p = 0.769), definite PET (r = 0.12, p = 0.451), and possible PET group (r = 0.12, p = 0.451). CONCLUSION: The current system is more useful in the objective assessment of autophony during phonation by calculating the ratio of voice sound and elicited noise sound transmitted in the EAC (EAC/Voice). This method seems promising because it is able to detect cases eluding conventionally used test methods such as sonotubometry performed without phonation, thereby increasing the accuracy of PET diagnoses.

Diagnosis of the Patulous Eustachian Tube.

OBJECTIVES: To review the diagnosis of patulous Eustachian tube (PET) based on the diagnostic criteria for the PET proposed by Japan Otological Society (JOS). METHODS: We reviewed typical aural symptoms of PET, Eustachian tube (ET) obstruction procedure to confirm diagnosis of PET, objective findings of a patent ET obtainable from observation of the movement of the tympanic membrane, and by ET function tests (tubo-tympano-aerodynamic graphy, sonotubometry). In addition, usefulness of other tests such as patulous Eustachian tube handicap inventory-10 (PHI-10), sonotubometry with postural change (Ohta method), and sitting computed tomography (CT) to diagnose PET is described. RESULTS AND CONCLUSIONS: We have described the diagnosis of PET based on the diagnostic criteria for PET proposed by JOS; PHI-10, Ohta method, and sitting CT are also useful for the diagnosis of PET. Further investigation is needed for an accurate diagnosis and precise evaluation of the pathophysiology of this challenging disease.

Plug size selection protocol for the treatment of intractable patulous Eustachian tube with Kobayashi Plug.

Background: There have been no useful criteria for initial plug size selection protocol for the treatment of intractable patulous Eustachian tube (PET). Aims/objectives: To establish a method for appropriate plug size selection using tubal function test and subjective symptom severity in PET patients who were treated by Kobayashi Plug insertion. Material and methods: A retrospective survey of medical records identified 39 ears of 35 patients with PET who received insertion of the Kobayashi Plug and whose PET symptoms were thereafter controlled for at least 6 months after surgery. Method: The evaluation scale of PET handicap inventory-10 (PHI-10) was used to indicate PET subjective symptom severity. Tubal function tests (sonotubometry and tubo-tympano-aerodynamic-graphy: TTAG) were performed. Results: There was no correlation between the preoperative PHI 10 score and plug size (p = .157). There was a significant correlation between the preoperative sound attenuation from nostril to EAC measured by sonotubometry and plug size (p < .001). There was no correlation between the preoperative pressure transmission ratio estimated by TTAG and plug size (p = .271). Conclusions and Significance: Sonotubometry which evaluates sound attenuation from nostril to EAC can be a useful tool for selecting plug size.

Patulous Eustachian tube (PET), a practical overview.

Symptoms of patulous Eustachian tube (ET), particularly autophony, can overlap with other conditions, and can arise from a variety of causes. We review the pathophysiology of "speech hyper-resonance syndromes", and possible mechanisms, including resonances in the tympanic membrane, Eustachian tube and nasopharynx. Treatment can be directed at the eardrum or the ET depending on site of pathology. We review typical presentations, examination findings, and useful clinical tests to distinguish PET from other disorders, and our philosophy of management.

Transmission of a novel sonotubometry acoustic click stimulus in healthy and patulous eustachian tube subjects: a retrospective case -control study.

BACKGROUND: Eustachian tube (ET) dysfunction can be very difficult to diagnose accurately. Our aim is to determine whether a newly developed sonotubometric test using clicks can reliably detect ET opening during swallowing in normal ET subjects, and patulous ET (PET) in subjects with ET dysfunction. METHODS: Sixteen subjects (19 normal ET ears and 6 PET ears) were individually placed in a sound-isolated audiometry booth and subjected to a 1000Hz click train stimulus, played through the nose. PET subjects were identified through the ET clinic at our institution, while healthy subjects were recruited. Transmission through the ET was recorded by a microphone in the ear ipsilateral to the presenting nostril, during no swallow and swallow states, and this was used to compute a power ratio (power in the frequency range of interest to the whole frequency range). The power transmission ratio both before and after the swallow was averaged, and represented the baseline (BaseR). The power transmission ratio during swallow represented the peak (PeakR). The same process was repeated in the absence of a stimulus to account for swallowing noise. Wilcoxon rank rum tests were performed to determine statistical significance. RESULTS: It was found that for healthy ET patients, the median difference between the PeakR and BaseR was 0.51 (p = 0.004). For the PET patients in this study, the median difference between the PeakR and the BaseR was 3.30 (p = 0.041). Comparing the baseline between groups revealed that PET patients had a median BaseR 1.05 higher than healthy ET patients. PET patients had a median PeakR of 3.84 higher than healthy ET patients. Both were deemed to be statistically significant (p = 0.003, p = 0.003 respectively). A significant difference was found between median PeakR for the stimulus and no-stimulus condition for the healthy ET group (0.59, p < 0.001) and for the PET group (4.39, p = 0.031), indicating that it was unlikely that swallowing noise caused false positive results. CONCLUSION: The results of this study suggest that a novel click stimulus is capable of detecting ET opening during swallowing in healthy patients as well as highlighting PET in diseased subjects.

Correlations between videoendoscopy and sonotubometry of eustachian tube opening during a swallow.

OBJECTIVES/HYPOTHESIS: Describe the relationship between the magnitude of eustachian tube (ET) dilation during swallowing observed on transnasal videoendoscopy and quantified by sonotubometry. STUDY DESIGN: Descriptive observational study. METHODS: Simultaneous transnasal videoendoscopic and sonotubometric recordings were done on 33 adults with no middle ear disease. Briefly, microphones were placed in the ear canals, a 45° telescope introduced through one side of the nose to visualize and record ipsilateral ET movements, and the probe from a sound generator placed in the opposite nostril. At a generated nasopharyngeal sound level, ET movements and ipsilateral microphone signals were continuously recorded while the subject performed a series of three swallows. For each swallow, relational movements among ET structures observed on video recordings and characteristics of the sonotubometry signal envelope at the ear canal were quantified at three times: swallow onset (T1), maximum soft-palate elevation (T2), and maximum ET luminal dilation (T3). RESULTS: A total of 99 swallows were analyzed. The average medial rotation of the ET cartilage and lateral wall over the T1-T2 interval were -32.7 ± 14.9° and 7.2 ± 25.1°, and over the T2-T3 interval were 4.6 ± 7.7° and 6.2 ± 14.6°, respectively. The transtubal sound transmission during a swallow peaked at an amplitude of 30.5 ± 35.7 mV during the 572.5 ± 292.6 ms of elevated sound-pressure time. Correlational analysis documented significant linear associations between the relational measures of ET component movements from videoendoscopy and the signal envelope measures from sonotubometry. CONCLUSIONS: There is a direct linear relationship between the degree of ET luminal dilation visualized on videoendoscopy and represented in the sonotubometry signal envelope. LEVEL OF EVIDENCE: NA Laryngoscope, 126:2778-2784, 2016.

Interpretation of sonotubometric data based on phase-shift detection.

BACKGROUND: Sonotubometry is a non-invasive means of assessing Eustachian tube (ET) function. Its interpretation remains a complex task with questionable results due to wide variation between trials. A study was conducted to ascertain whether the measurement of phase shift in sonotubometric signals would be a more reliable indicator of ET patency than fluctuating Sound Pressure Level (SPL). METHODS: The ears of six healthy participants and two participants with patulous ET (PET) were probed with a 100 Hz signal. Five recordings of SPL were performed at the external auditory canal. Cross-correlation was performed among filtered SPL signals and among extracted phase shift waveforms. Peak coefficients were averaged to provide a measure of waveform similarity between trials. RESULTS: Mean peak cross correlation coefficient for SPL signal measured 0.603 ± 0.057 Standard Error of Mean (SEM) whilst that for Phase-Shift signal measured 0.884 ± 0.027 (SEM). All normal participants demonstrated an observable phase change between the ear and nasal signal during swallowing indicating an acoustic impedance change during the event. For the PET patients tested, the phase measurements in ear and nasal signals follow one another reasonably closely, indicating little or no impedance change during swallowing. It is thought that this impedance change is indicative of opening of the ET in normal patients, and the lack impedance change indicates ET either remaining open or remaining closed throughout the swallow. CONCLUSIONS: Experimental data suggest that phase-shift detection is a more consistent means of interpreting sonotubometric data than SPL analysis.

Sonotubometry, a useful tool for the evaluation of the Eustachian tube ventilatory function.

From the three Eustachian tube (ET) functions: middle ear protection, secretion clearance and middle ear ventilation, the ventilatory function is unanimously considered the most important one, because proper hearing is established only when tympanic membrane compliance is normal. This requires equilibrium between the middle ear and ambient gas pressure, which makes the normal functioning of active ET opening of critical importance. There are several methods and tests that can assess such a complex and variable mechanism. Sonotubometry is one such method; despite the fact that it has been continuously improved in the last 20 years, it is not yet systematically used to evaluate the ET ventilatory function, because its measurement pattern, context mapping (patient, clinic data, medication, treatment), validation, reproducibility and value for clinic practice, have not yet been fully consolidated and integrated in a knowledge-based, service-oriented system, that can provide decision support or even diagnostic. The paper reviews the role of tubal sonometry as a non-invasive, physiologic and easy to use method in assessing the ventilatory function and investigates the validity and reproducibility of a measuring pattern and test in a group of children. The paper describes the test pattern used, and the computer-based platform based on: (1) Digital Signal Processing (DSP) for sound acquisition and low-level processing; (2) Artificial Intelligence techniques to extract significant sound features from sonotubograms and learn a manifold context database. Results are reported from test series carried out in healthy children; a similar study between tests is included in the final Discussions section.

Eustachian tube opening measured by sonotubometry is poorer in adults with a history of past middle ear disease.

OBJECTIVE: Test the hypothesis that active Eustachian tube opening efficiency as measured by sonotubometry is higher in adults with no extant middle-ear disease and no history of previous otitis media (Group-1) when compared to adults with no middle-ear disease but a positive history for otitis media (Group-2). METHODS: Eustachian tube function for 1 ear of 33 otherwise healthy adult subjects, 16 assigned to Group-1 and 17 to Group-2, was tested by sonotubometry using a standard protocol. For each test, the sound envelopes for 3 swallows were abstracted independently by 2 observers from the data stream and 7 descriptive parameters related to sound envelope "shape" were calculated. Inter-relatedness among the values for the parameters was explored using correlation analysis. The contributions of swallow, observer and group to the variance in each parameter were evaluated for significance using a General Linear Model. RESULTS: The shape parameters reflecting envelope height, area and rise and fall rates were highly inter-correlated, but those reflecting envelope widths were not. There was no effect of "swallow" on any of the parameters; but there was a significant "observer" effect on all measures of envelope width, greater for observer-2, and a significant "group" effect for 5 of the 7 shape parameters, all greater in Group-1. CONCLUSIONS: Quantifiable measures of the sound signal "shape" recorded by sonotubometry during swallowing were significantly different between the 2 groups of subjects. This is interpretable as evidencing a more efficient Eustachian tube opening-function in adults with healthy middle ears who do not have a previous history of otitis media when compared to similar adults with a history of prior otitis media. Inefficient Eustachian tube function as children may not be completely resolved by adulthood increasing adult otitis media risk when Eustachian tube function is down-graded by extant upper respiratory diseases that provoke nasopharyngeal inflammation.