Surprising discovery of an enigmatic geometrid in Croatia: Mirlatiaarcuata, gen. nov., sp. nov. (Lepidoptera, Geometridae).

A new monotypic genus of Geometridae, Mirlatiagen. nov., and a new species, M.arcuatasp. nov., are described from Croatia. Based on external and genitalia characters, the new genus is tentatively placed in the subfamily Larentiinae. However, the new genus takes a highly isolated position by having unique characters of the tympanum and showing an unusually long pectination of female antennae. Genetic analysis of a fragmented DNA barcode (mtDNA; cytochrome c oxidase 1) did not result in a clear assignation to any geometrid subfamily or tribe. Adults, male and female genitalia, and habitat photos of the type locality of the new species are illustrated.

DPOAEs and tympanal membrane vibrations reveal adaptations of the sexually dimorphic ear of the concave-eared torrent frog, Odorrana tormota.

While most anuran species are highly vocal, few of them seem to be endowed with a complex call repertoire. Odorrana tormota, combines a remarkable vocalization complexity with auditory sensitivity over an extended spectral range spanning from audible to ultrasonic frequencies. This species is also exceptional for its ability to modify its middle ear tuning by closing the Eustachian tubes (ET). Using scanning laser Doppler vibrometry, the tympanal vibrations were measured to investigate if the tuning shift caused by the ET closure contributes to intraspecific acoustic communication. To gain insight into the inner ear frequency selectivity and sensitivity of this species, distortion product otoacoustic emissions were recorded at multiple frequency-level combinations. Our measurements of inner ear responses indicated that in O. tormota each sex is more sensitive to the frequencies of the other sex's vocalizations, female ears are more sensitive to 2-7 kHz, while male ears are more sensitive to 3-15 kHz. We also found that in both sexes the ET closure impacts the sensitivity of the middle and inner ear at frequencies used for communication with conspecifics. This study broadens our understanding of peripheral auditory mechanisms contributing to intraspecific acoustic communication in anurans.

Development and Validation of a Clinical Score for Predicting the Risk of Tympanosclerosis Before Surgery.

OBJECTIVE: To develop and validate a clinical score to predict the risk of tympanosclerosis before surgery. METHODS: A sample of 404 patients who underwent middle ear microsurgery for otitis media was enrolled. These patients were randomly divided into 2 cohorts: the training cohort (n = 243, 60%) and the validation cohort (n = 161, 40%). The preoperative predictors of tympanosclerosis were determined by multivariate logistic regression analysis and implemented using a clinical score tool. The predictive accuracy and discriminative ability of the clinical score were determined by the area under the curve (AUC) and the calibration curve. RESULTS: The multivariate analysis in the training cohort (n = 243, 60%) identified independent factors for tympanosclerosis as the female sex (odds ratio [OR]: 3.83; 95% CI: 1.66-9.37), the frequency-specific air-bone gap at 250 Hz ≥ 45 dB HL (OR: 3.68; 95% CI: 1.68-8.57), aditus ad antrum blockage (OR: 3.29; 95% CI: 1.38-8.43), type I eardrum calcification (OR: 25.37; 95% CI: 8.41-88.91) or type II eardrum calcification (OR: 18.86; 95% CI: 6.89-58.77), and a history of otitis media ≥ 10 years (OR: 4.10; 95% CI: 1.58-11.83), which were all included in the clinical score tool. The AUC of the clinical score for predicting tympanosclerosis was 0.89 (95% CI: 0.85-0.93) in the training cohort and 0.89 (95% CI: 0.84-0.95) in the validation cohort. The calibration curve also showed good agreement between the predicted and observed probability. CONCLUSIONS: The clinical score achieved an optimal prediction of tympanosclerosis before surgery. The presence of calcification pearls on the promontorium tympani is a strong predictor of tympanosclerosis with stapes fixation.

Comparison between postauricular steroid injection and intratympanic steroid perfusion for refractory severe and profound sudden sensorineural hearing loss.

BACKGROUND: To analyze the clinical efficacy of intratympanic steroid perfusion (ISP) and postauricular steroid injection (PSI) for refractory severe and profound sudden sensorineural hearing loss (SSNHL). METHODS: SSNHL patients who failed a conventional treatment with severe to profound hearing loss [pure tone average (PTA, 0.25-8 kHz) > 60 dB] were treated with ISP or PSI plus antioxidant and neurotrophin for 10 consecutive days. Antioxidant and neurotrophin were administrated either intravenously and/or orally. All patients were assigned into the ISP group or the PSI group and followed up for more than three months. The changes in PTA, effective rate and side effects were analyzed in the two groups. RESULTS: Similar hearing improvements and effective rates were observed in the two groups. However, a slightly better efficacy was observed in the PSI group compared to the ISP group. Patients with shorter intervals from onset to treatment had significantly more hearing improvements. The route of antioxidant and neurotrophin administration had no impact on treatment effects. CONCLUSION: Both ISP and PSI could be used as salvage treatments for refractory SSNHL. These salvage treatments should be started as soon as possible once SSNHL patients fail a conventional treatment.

Shedding light on the tympanic membrane: a brief history of the description and understanding of its anatomy.

OBJECTIVE: For centuries, the tympanum has remained the only visible structure of the organ of hearing. This study aimed to trace the understanding of the tympanic membrane from antiquity to the early twentieth century. METHODS: A review was conducted of primary and secondary historical and scientific literature describing the tympanic membrane anatomy. RESULTS: Although ancient polymaths sensed that sounds were vibrations that could spread in the air and be perceived by the hearing organ, there were numerous misconceptions about the tympanum until human dissections performed during the Renaissance. The tympanum was correctly described only centuries later when technological advances enabled otologists to understand it as a fundamental part of the hearing organ. CONCLUSION: The tympanic membrane history reflects key stages in medical knowledge; limited for centuries, a great technological leap was possible in the nineteenth century, contributing to the emergence of otologists and laying the foundations of modern otology.

Anatomical, Histological, and Electron Microscopic Structures of Syrinx in Male Budgerigars (Melopsittacus undulatus).

The syrinx is the main source for phonation in birds, its function is analogous to the mammalian larynx. Birds have both a larynx and a syrinx, but they use only the latter to vocalize. The objective of this work to give a detailed description of the anatomical, histological, and ultrastructural of syrinx in male budgerigars as a model of a passerine bird. The syrinx in the current study was to be found as a tracheobronchial type, it consists of cranial (tympanum) part and caudal (bronchosyringeal) part and, additionally, there are lateral vibrating membranes. The tympanum is formed of the last six tracheal rings, histologically its lamina epithelialis is a pseudostratified ciliated columnar epithelium with goblet cells and interrupted by intraepithelial glands. The secretory acini appear oval and lined by pyramidal secretory cells. The lamina propria­submucosa contain numerous blood capillaries, immune cells, and telocytes (TCs). The electron microscopic examination revealed numerous blood capillaries surrounded by fibroblasts and numerous immune cells, including mast cells and wandering leukocytes, within the tympanum mucosa. Hence, this study provides a detailed knowledge about the syrinx in male budgerigars.

Sexual dimorphism in external morphology of the American bullfrog Rana (Aquarana) catesbeiana and the possibility of sex determination based on tympanic membrane/eye size ratio.

The American bullfrog Rana (Aquarana) catesbeiana has been reported to show significant sexual dimorphism based on the size ratio between the tympanic membrane and the eye. In males the tympanic membrane is much larger than the eye, but not in females. The ratio has been used as a convenient criterion to discriminate sexes (sexing) in the American bullfrog, though its reliability is unknown. In this study, we examined 86 adult American bullfrogs to clarify whether the tympanic membrane long diameter/eye long diameter (Dtm/De) ratio is a reliable index to discriminate sexes in this species. In addition, we examined the growth of this sexually dimorphic trait. Results indicated that there is a significant difference but there is a small overlap in this ratio Dtm/De between sexes. The allometric comparisons showed the sexual dimorphism of the Dtm/De ratio was increased during growth and the dimorphism is attributable to the difference in the growth rate of the tympanic membrane (Dtm). Therefore, sex determination of American bullfrogs cannot be wholly reliably achieved by the Dtm/De ratio alone; other external morphological features are required in addition.

Tympanum reconstruction using a sternocleidomastoid flap in patients with lateral skull base lesions: surgical technique and clinical report.

BACKGROUND: During surgical treatment of lesions involving the skull base, conductive hearing is often sacrificed due to tympanum destruction. This study aimed to develop a method for tympanum reconstruction using a sternocleidomastoid (SCM) flap to preserve conductive hearing during lateral skull base surgery. METHODS: This study included five patients with lateral skull base lesions who underwent surgery including tympanum reconstruction with an SCM flap between July 2015 and November 2017. RESULTS: Three patients seen with facial nerve schwannoma, and two had paraganglioma of the head and neck. All patients' inferior and posterior tympanic walls were resected; the tympanum and ossicular chain were reconstructed with an SCM flap and prosthesis. The mean postoperative air-bone gap was 14 dB. No lesion recurrences were observed until the last follow-up. CONCLUSION: The SCM flap is effective in preserving conductive hearing through reconstruction of the inferior and posterior tympanic walls in lateral skull base surgery.

Applied anatomy of round window and adjacent structures of tympanum related to cochlear implantation / Anatomia aplicada da janela redonda e estruturas adjacentes relacionadas ao implante coclear

Abstract Introduction: Various aspects of the round window anatomy and anatomy of posterior tympanum have relevant implications for designing cochlear implant electrodes and visualizing the round window through facial recess. Preoperative information about possible anatomical variations of the round window and its relationships to the adjacent neurovascular structures can help reduce complications in cochlear implant surgery. Objective: The present study was undertaken to assess the common variations in round window anatomy and the relationships to structures of the tympanum that may be relevant for cochlear implant surgery. Methods: Thirty-five normal wet human cadaveric temporal bones were studied by dissection for anatomy of round window and its relation to facial nerve, carotid canal, jugular fossa and other structures of posterior tympanum. The dissected bones were photographed by a digital camera of 18 megapixels, which were then imported to a computer to determine various parameters using ScopyDoc 8.0.0.22 version software, after proper calibration and at 1× magnification. Results: When the round window niche is placed posteriorly and inferiorly, the distance between round window and vertical facial nerve decreases, whereas that with horizontal facial nerve increases. In such cases, the distance between oval window and round window also increases. Maximum height of the round window in our study ranged from 0.51-1.27 mm (mean of 0.69 ± 0.25 mm). Maximum width of round window ranged from 0.51 to 2.04 mm (mean of 1.16 ± 0.47 mm). Average minimum distance between round window and carotid canal was 3.71 ± 0.88 mm (range of 2.79-5.34 mm) and that between round window and jugular fossa was 2.47 ± 0.9 mm (range of 1.24-4.3 mm). Conclusion: The distances from the round window to the oval window and facial nerve are important parameters in identifying a difficult round window niche. Modification of the electrode may be a better option than drilling off the round window margins for insertion of cochlear implant electrodes.

Resumo Introdução: Vários aspectos da anatomia da janela redonda e da anatomia da caixa timpânica posterior são relevantes, devido a suas implicações no desenho dos eletrodos para o implante coclear e na visibilidade da janela redonda através do recesso facial. Informações prévias sobre possíveis variações anatômicas da janela redonda e suas relações com as estruturas neurovasculares adjacentes podem ajudar a reduzir as complicações dessa cirurgia. Objetivo: O presente estudo foi realizado para avaliar as diversas variações da anatomia da janela redonda e sua relação com as estruturas adjacentes, o que pode ser relevante para a cirurgia de implante coclear. Método: Trinta e cinco ossos temporais normais de cadáveres humanos frescos foram dissecados para avaliação da anatomia da janela redonda e sua relação com o nervo facial, canal carotídeo, fossa jugular e outras estruturas da caixa timpânica posterior. Os ossos dissecados foram fotografados com uma câmera digital de 18 megapixels e as imagens importadas para um computador para determinar diversos parâmetros, utilizando-se o software ScopyDoc versão 8.0.0.22, após a calibração adequada e com ampliação de 1×. Resultados: Quando o nicho da janela redonda se encontra posicionado posteriormente e inferiormente, a distância entre a janela redonda e o nervo facial vertical diminui, enquanto aquela com o nervo facial horizontal aumenta. Em tais casos, a distância entre a janela oval e a janela redonda também aumenta. A altura máxima da janela redonda em nosso estudo variou de 0,51 a 1,27 mm (média de 0,69 ± 0,25 mm). A largura máxima da janela redonda variou de 0,51 a 2,04 mm (média de 1,16 a 0,47 mm). A distância mínima média entre a janela redonda e o canal carotídeo foi de 3,71 ± 0,88 mm (variação de 2,79 a 5,34 mm) e entre a janela redonda e a fossa jugular, em nosso estudo, foi de 2,47 ± 0,9 mm (variação de 1,24 ± 4,3 mm). Conclusão: A distância da janela redonda a partir da janela oval e do nervo facial são parâmetros importantes para a identificação do difícil nicho da janela redonda. A modificação do desenho do eletrodo pode ser uma opção melhor do que o broqueamento das margens da janela redonda para a inserção dos eletrodos no implante coclear.

Applied anatomy of round window and adjacent structures of tympanum related to cochlear implantation.

INTRODUCTION: Various aspects of the round window anatomy and anatomy of posterior tympanum have relevant implications for designing cochlear implant electrodes and visualizing the round window through facial recess. Preoperative information about possible anatomical variations of the round window and its relationships to the adjacent neurovascular structures can help reduce complications in cochlear implant surgery. OBJECTIVE: The present study was undertaken to assess the common variations in round window anatomy and the relationships to structures of the tympanum that may be relevant for cochlear implant surgery. METHODS: Thirty-five normal wet human cadaveric temporal bones were studied by dissection for anatomy of round window and its relation to facial nerve, carotid canal, jugular fossa and other structures of posterior tympanum. The dissected bones were photographed by a digital camera of 18 megapixels, which were then imported to a computer to determine various parameters using ScopyDoc 8.0.0.22 version software, after proper calibration and at 1× magnification. RESULTS: When the round window niche is placed posteriorly and inferiorly, the distance between round window and vertical facial nerve decreases, whereas that with horizontal facial nerve increases. In such cases, the distance between oval window and round window also increases. Maximum height of the round window in our study ranged from 0.51-1.27mm (mean of 0.69±0.25mm). Maximum width of round window ranged from 0.51 to 2.04mm (mean of 1.16±0.47mm). Average minimum distance between round window and carotid canal was 3.71±0.88mm (range of 2.79-5.34mm) and that between round window and jugular fossa was 2.47±0.9mm (range of 1.24-4.3mm). CONCLUSION: The distances from the round window to the oval window and facial nerve are important parameters in identifying a difficult round window niche. Modification of the electrode may be a better option than drilling off the round window margins for insertion of cochlear implant electrodes.

[Surgical treatment of external auricular cholesteatoma involving tympanum and papilloma].

Objective:To explore the operation treatments and their outcomes of external auditory canal cholesteatomas involving the tympanic cavity and mastoid process. Method:Forty-two patients (45 ears) with external auditory canal cholesteatomas were included in this study who were operated. All lesions invaded the tympanic cavity and mastoid process. Excision of cholesteatoma, external auditory canal angioplasty and concha formation were performed. Ossicular chain reconstruction was performed in 3 ears. Mastoidectomy with close technique were performed in 4 ears. Open radical mastoidectomy was performed in 5 ears. Posterior bone-wall of auricular meatus reconstruction was performed in 3 ears. Tympanoplasty was performed in 21 ears. Pure tone audiogram and aural endoscope were carried out after the operation (3 months, 6months, 1 year, 2 years, 3 years…). Result:Stricture of external auditory meatus were occured in 2 ears in 2 and 3 months after surgery respectively. Cholesteatoma recurrence was observed in 2 ears in 1 year after operation. Wet ear was observed in 1 patient and then another operation was performed after 7 months. Besides the patients above, the epitheliums of the cavity were well in all other patients with complete tympanic membranes. Hearing was improved in all patients (hearing by air conduction:5－30 dB HL). Conclusion:According to the range of the external auditory canal cholesteatoma, we took different operation methods including tympanoplasty, open or close radical mastoidectomy and reconstruction of posterior wall of external auditory canal etc. Those methods, including external auditory canal angioplasty, cavity plasty of concha and skin grafting of external auditory canal, could help to prevent scar formation and stricture of external auditory canal, prevent cholesteatoma recurrence and improve hearing.

Evolution of Sound Source Localization Circuits in the Nonmammalian Vertebrate Brainstem.

The earliest vertebrate ears likely subserved a gravistatic function for orientation in the aquatic environment. However, in addition to detecting acceleration created by the animal's own movements, the otolithic end organs that detect linear acceleration would have responded to particle movement created by external sources. The potential to identify and localize these external sources may have been a major selection force in the evolution of the early vertebrate ear and in the processing of sound in the central nervous system. The intrinsic physiological polarization of sensory hair cells on the otolith organs confers sensitivity to the direction of stimulation, including the direction of particle motion at auditory frequencies. In extant fishes, afferents from otolithic end organs encode the axis of particle motion, which is conveyed to the dorsal regions of first-order octaval nuclei. This directional information is further enhanced by bilateral computations in the medulla and the auditory midbrain. We propose that similar direction-sensitive neurons were present in the early aquatic tetrapods and that selection for sound localization in air acted upon preexisting brain stem circuits like those in fishes. With movement onto land, the early tetrapods may have retained some sensitivity to particle motion, transduced by bone conduction, and later acquired new auditory papillae and tympanic hearing. Tympanic hearing arose in parallel within each of the major tetrapod lineages and would have led to increased sensitivity to a broader frequency range and to modification of the preexisting circuitry for sound source localization.

Aberrant sylvian vein: A newly described cause of pulsatile tinnitus.

We herein report a newly described cause of venous pulsatile tinnitus: protrusion of an aberrant sylvian vein into the tympanum. A 60-year-old woman presented with a 4-month history of objective persistent pulsatile tinnitus in the right ear with no other complaints. The pulsatile tinnitus diminished with rotation of the head to the right side or by compression of the right cervical vascular structures. The frequency and intensity of the tinnitus were 125 Hz and 20 dB HL, respectively. Audiometry and otoscopic examination findings were normal. Radiologic examination showed that the right sylvian vein protruded into the tympanum through the dehiscent anterior cortical plate of the tympanum.

Hearing on the fly: the effects of wing position on noctuid moth hearing.

The ear of the noctuid moth has only two auditory neurons, A1 and A2, which function in detecting predatory bats. However, the noctuid's ears are located on the thorax behind the wings. Therefore, as these moths need to hear during flight, it was hypothesized that wing position may affect their hearing. The wing was fixed in three different positions: up, flat and down. An additional subset of animals was measured with freely moving wings. In order to negate any possible acoustic shadowing or diffractive effects, all wings were snipped, leaving the proximal-most portion and the wing hinge intact. Results revealed that wing position plays a factor in threshold sensitivity of the less sensitive auditory neuron A2, but not in the more sensitive neuron A1. Furthermore, when the wing was set in the down position, fewer A1 action potentials were generated prior to the initiation of A2 activity. Analyzing the motion of the tympanal membrane did not reveal differences in movement due to wing position. Therefore, these neural differences arising from wing position are proposed to be due to other factors within the animal such as different muscle tensions.

[Intratympanic methylprednisolone perfusion remedy refractory sudden sensorineural hearing loss].

Objective:To observe the clinical efficacy and characteristics of intratympanic methylprednisolone perfusion (IMP) as a salvage treatment in sudden sensorineural hearing loss（SSNHL） patients who failed in conventional treatments.Method:One hundred and ten SSNHL patients who failed to respond to conventional therapies were recruited. And a 10-day IMP was adopted as a salvage treatment to improve their hearing. Twenty five SSNHL patients who failed to respond to conventional therapies and without any other treatment were recruited as control group. The pure tone average(PTA) before and after IMP treatment was observed by pure tone audiometry. Data analysis was performed using SPSS13.0 and test level was set α=0.05. Result:The total effective rate of IMP was 49.09%, significantly higher than control group 16.00%. Significant hearing improvement was observed at all frequencies after IMP treatment. Especially PTA gain at the low frequencies was (13.45±18.10) dB, obviously higher than high frequency. An obvious improvement of PTA were detected in profound group(15.62±13.95)dB compared with in moderate group(7.97±14.90) dB and in severe groupï¼»PTA gain(5.59±13.88) dBï¼½. However, there was no significant difference between the two latter groups. PTA gain was(12.26±14.69) dB,(13.37±17.11) dB and (3.21±10.51) dB respectively in patients who suffer from SSNHL within 2 weeks, >2-4 weeks and over 4 weeks. Whether accompanied with vertigo or tinnitus had no significant influence on the efficacy of IMP treatment in SSNHL patients who failed investigated. Conclusion:IMP treatment could improve the hearing in SSNHL patients who failed to respond to conventional therapies. The gain was closely related to the onset time and the severity of hearing loss before IMP treatment.

[Comparative study of intratympanic Dexamethasone injection for sudden deafness at different time intervals].

Objective:Comparative study of intratympanic Dexamethasone injection for sudden deafness at different time intervals. Method:One hundred and sixty cases which had been diagnosed sudden deafness were treated by vasodilatortrophic nerve drugs and high pressure oxygen and the same time dexamethasone injective in the middle ear. Injection time intervals were divided into qd, qod, and twice a week. Contral group is not use dexamethasone. Result:The cure rate of qd and qod groups were higher than twice a week group, and the difference was statistically significant (P<0.05). Conclusion:Intratypanic Dexamethasone injection for sudden deafness qd or qod is effective and safe.

[Intratympanic steroid intervention as initial therapy for sudden sensorineural hearing loss: a systematic review of reviews].

Objective:The aim of this overview is to evaluate the relevant systematic reviews and Meta-analysis that focus on intratympanic steroid intervention as initial therapy for sudden sensorineural hearing loss.Method:The literature search was based on the published systematic reviews and Meta analysis. According to the include and exclude critera, the important data was extracted. Quality assessment was rigorously performed using the 11-item Assessment of Multiple Systematic Reviews (AMSTAR) and main outcome indicators of literature evidence quality were evaluated by Grading of Recommendations, Assessment, Development and Evaluation (GRADE).Result:Sixteen related systemic reviews and Meta-analysis (6 Chinese literatures and 10 English literatures) published during 2009-2016 were included; AMSTAR score was 4 to 9 points,14 studies was medium quality and 2 was high quality. However, the clinical evidence was controversial and there is no consensus regarding the efficacy of intratympanic steroid therapy for sudden sensorineural hearing loss.Conclusion:As an initial treatment, there is no sufficient high quality evidence to recommend the ITS therapy. There is a need for further systematic reviews that adhere to strict scientific methods.

The Clinical Application of Eucalyptol, Limonene and Pinene Enteric Soft Capsules in the Treatment of the Prophylaxis of Tympanum Fluid in Secretory Otitis Media in Children / 听力学及言语疾病杂志

Objective To investigate the effects of the eucalyptol,limonene and pinene enteric soft capsules (mucoregulatory agents) in preventing from tympanum fluid in children.Methods A total of 341 children (497 ears) with acute otitis media were randomly divided into two groups:the experimental group and the control group.The experimental group was given symptomatic treatment and oral in-take of the eucalyptol,limonene and pinene enteric soft capsules,while the control group with acute otitis media received conventional symptomatic treatment.All the patients were followed-up 7 and 14 days after treatment.Clinical data were collected,including symptoms,and tympanogram changes.Results Seven days after the initial treatment,tympanum fluid occurred in 110 cases of 170 ears(65.09％,110/170) in the control group,and in 51 cases of 70 ears (29.65％,51/172) in the experimental group.The difference was statistically significant (P＜0.01).After 14 days,41 cases (66 ears)of tympanum fluid occurred in the control group (24.26％,41/169),32 cases(36 ears) of otitis media (18.60％,32/172) occurred in the experimental group.The difference was statistically significant (P＜0.01).In the control group,the tympanum fluid disappeared in 54 cases(60 ears) after regular treatment 72.0％,54/75),and reliefed in 15 cases(22 ears) with irregular treatment (42.86％,15/35).The difference was statistically significant (P＜0.01).Conclusion Eucalyptol,limonene and pinene enteric soft capsules can effectively reduce the incidence of tympanum fluid in children with acute otitis media.Mucoregulatory agents may promote the eduction of effusion.

Auditory mechanics in a bush-cricket: direct evidence of dual sound inputs in the pressure difference receiver.

The ear of the bush-cricket, Copiphora gorgonensis, consists of a system of paired eardrums (tympana) on each foreleg. In these insects, the ear is backed by an air-filled tube, the acoustic trachea (AT), which transfers sound from the prothoracic acoustic spiracle to the internal side of the eardrums. Both surfaces of the eardrums of this auditory system are exposed to sound, making it a directionally sensitive pressure difference receiver. A key feature of the AT is its capacity to reduce the velocity of sound propagation and alter the acoustic driving forces at the tympanum. The mechanism responsible for reduction in sound velocity in the AT remains elusive, yet it is deemed to depend on adiabatic or isothermal conditions. To investigate the biophysics of such multiple input ears, we used micro-scanning laser Doppler vibrometry and micro-computed X-ray tomography. We measured the velocity of sound propagation in the AT, the transmission gains across auditory frequencies and the time-resolved mechanical dynamics of the tympanal membranes in C. gorgonensis Tracheal sound transmission generates a gain of approximately 15 dB SPL, and a propagation velocity of ca 255 m s-1, an approximately 25% reduction from free field propagation. Modelling tracheal acoustic behaviour that accounts for thermal and viscous effects, we conclude that reduction in sound velocity within the AT can be explained, among others, by heat exchange between the sound wave and the tracheal walls.

Simultaneous versus Sequential Intratympanic Steroid Treatment for Severe-to-Profound Sudden Sensorineural Hearing Loss.

OBJECTIVES: Severe-to-profound sudden sensorineural hearing loss (SSNHL) has a poor prognosis. We aimed to compare the efficacy of simultaneous and sequential oral and intratympanic steroids for this condition. METHODS: Fifty patients with severe-to-profound SSNHL (>70 dB HL) were included from 7 centers. The simultaneous group (27 patients) received oral and intratympanic steroid injections for 2 weeks. The sequential group (23 patients) was treated with oral steroids for 2 weeks and intratympanic steroids for the subsequent 2 weeks. Pure-tone averages (PTA) and word discrimination scores (WDS) were compared before treatment and 2 weeks and 1 and 2 months after treatment. Treatment outcomes according to the modified American Academy of Otolaryngology-Head and Neck Surgery (AAO-HNS) criteria were also analyzed. RESULTS: The improvement in PTA and WDS at the 2-week follow-up was 23 ± 21 dB HL and 20 ± 39% in the simultaneous group and 31 ± 29 dB HL and 37 ± 42% in the sequential group; this was not statistically significant. Complete or partial recovery at the 2-week follow-up was observed in 26% of the simultaneous group and 30% of the sequential group; this was also not significant. The improvement in PTA and WDS at the 2-month follow-up was 40 ± 20 dB HL and 37 ± 35% in the simultaneous group and 41 ± 25 dB HL and 48 ± 41% in the sequential group; this was not statistically significant. Complete or partial recovery at the 2-month follow-up was observed in 33% of the simultaneous group and 35% of the sequential group; this was also not significant. Seven patients in the sequential group did not need intratympanic steroid injections for sufficient improvement after oral steroids alone. CONCLUSIONS: Simultaneous oral/intratympanic steroid treatment yielded a recovery similar to that produced by sequential treatment. Because the addition of intratympanic steroids can be decided upon based on the improvement after an oral steroid, the sequential regimen can be recommended to avoid unnecessary intratympanic injections.