ear ossicles

Summary

Summary: A mobile chain of three small bones (INCUS; MALLEUS; STAPES) in the TYMPANIC CAVITY between the TYMPANIC MEMBRANE and the oval window on the wall of INNER EAR. Sound waves are converted to vibration by the tympanic membrane then transmitted via these ear ossicles to the inner ear.

Top Publications

  1. SAnchez Villagra M, Gemballa S, Nummela S, Smith K, Maier W. Ontogenetic and phylogenetic transformations of the ear ossicles in marsupial mammals. J Morphol. 2002;251:219-38 pubmed
    ..skulls representing a wide range of taxa and aims at addressing several issues concerning the evolution of the ear ossicles in marsupials...
  2. Carrillo R, Yang N, Abes G. Probabilities of ossicular discontinuity in chronic suppurative otitis media using pure-tone audiometry. Otol Neurotol. 2007;28:1034-7 pubmed
    ..To analyze the likelihood ratios (LRs) and predictive values of preoperative air-bone gap (ABG) levels on the presence of gross ossicular discontinuity (OD) among chronic suppurative otitis media (CSOM) patients...
  3. Dornelles C, Rosito L, Meurer L, Costa S, Argenta A, Alves S. Hystology findings' correlation between the ossicular chain in the transoperative and cholesteatomas. Braz J Otorhinolaryngol. 2007;73:738-43 pubmed
    ..Chronic otitis media is hystopathologycaly defined as the presence of irreversible inflammatory tissue changes in the middle ear. Ossicular lesions represent the most prevalent change...
  4. Kinkel M, Thewissen J, Oelschläger H. Rotation of middle ear ossicles during cetacean development. J Morphol. 2001;249:126-31 pubmed
    ..Therefore, some of the unique characteristics of the cetacean middle ear develop as modifications of an initially terrestrial-like morphology...
  5. Chang E, Cheng J, Roosli C, Kobler J, Rosowski J, Yun S. Simultaneous 3D imaging of sound-induced motions of the tympanic membrane and middle ear ossicles. Hear Res. 2013;304:49-56 pubmed publisher
    Efficient transfer of sound by the middle ear ossicles is essential for hearing. Various pathologies can impede the transmission of sound and thereby cause conductive hearing loss...
  6. Jaryszak E, Sampson E, Antonelli P. Effect of ossicular prosthesis biofilms on middle ear scarring and hearing outcomes. Otol Neurotol. 2009;30:1191-5 pubmed publisher
    ..The purpose of this study was to determine if biofilms are present on ORPs in patients undergoing revision ossicular chain reconstruction and if their presence correlates with middle ear scarring or hearing outcomes...
  7. Lavender D, Taraskin S, Mason M. Mass distribution and rotational inertia of "microtype" and "freely mobile" middle ear ossicles in rodents. Hear Res. 2011;282:97-107 pubmed publisher
    ..Functional differences appear to exist even among rodent ears of the same general type, but the adaptive significance of these differences remains enigmatic...
  8. Jaryszak E, Sampson E, Antonelli P. Biofilm formation by Pseudomonas aeruginosa on ossicular reconstruction prostheses. Am J Otolaryngol. 2009;30:367-70 pubmed publisher
    ..The purpose of this experiment was to determine if PA forms biofilm on different ossicular chain reconstruction prostheses to a different degree...
  9. Jeng F, Tsai M, Brown C. Relationship of preoperative findings and ossicular discontinuity in chronic otitis media. Otol Neurotol. 2003;24:29-32 pubmed
    ..If preoperative information can be used to determine whether or not the ossicular chain is intact, the patient can be better informed and the surgeon can be better prepared before surgery...
  10. Xing F, Cao K. [Clinical study of congenital middle ear malformations]. Lin Chuang Er Bi Yan Hou Ke Za Zhi. 2004;18:586-9 pubmed
    ..To search into the diagnosis and treatment of congenital malformation of middle ear...

Detail Information

Publications62

  1. SAnchez Villagra M, Gemballa S, Nummela S, Smith K, Maier W. Ontogenetic and phylogenetic transformations of the ear ossicles in marsupial mammals. J Morphol. 2002;251:219-38 pubmed
    ..skulls representing a wide range of taxa and aims at addressing several issues concerning the evolution of the ear ossicles in marsupials...
  2. Carrillo R, Yang N, Abes G. Probabilities of ossicular discontinuity in chronic suppurative otitis media using pure-tone audiometry. Otol Neurotol. 2007;28:1034-7 pubmed
    ..To analyze the likelihood ratios (LRs) and predictive values of preoperative air-bone gap (ABG) levels on the presence of gross ossicular discontinuity (OD) among chronic suppurative otitis media (CSOM) patients...
  3. Dornelles C, Rosito L, Meurer L, Costa S, Argenta A, Alves S. Hystology findings' correlation between the ossicular chain in the transoperative and cholesteatomas. Braz J Otorhinolaryngol. 2007;73:738-43 pubmed
    ..Chronic otitis media is hystopathologycaly defined as the presence of irreversible inflammatory tissue changes in the middle ear. Ossicular lesions represent the most prevalent change...
  4. Kinkel M, Thewissen J, Oelschläger H. Rotation of middle ear ossicles during cetacean development. J Morphol. 2001;249:126-31 pubmed
    ..Therefore, some of the unique characteristics of the cetacean middle ear develop as modifications of an initially terrestrial-like morphology...
  5. Chang E, Cheng J, Roosli C, Kobler J, Rosowski J, Yun S. Simultaneous 3D imaging of sound-induced motions of the tympanic membrane and middle ear ossicles. Hear Res. 2013;304:49-56 pubmed publisher
    Efficient transfer of sound by the middle ear ossicles is essential for hearing. Various pathologies can impede the transmission of sound and thereby cause conductive hearing loss...
  6. Jaryszak E, Sampson E, Antonelli P. Effect of ossicular prosthesis biofilms on middle ear scarring and hearing outcomes. Otol Neurotol. 2009;30:1191-5 pubmed publisher
    ..The purpose of this study was to determine if biofilms are present on ORPs in patients undergoing revision ossicular chain reconstruction and if their presence correlates with middle ear scarring or hearing outcomes...
  7. Lavender D, Taraskin S, Mason M. Mass distribution and rotational inertia of "microtype" and "freely mobile" middle ear ossicles in rodents. Hear Res. 2011;282:97-107 pubmed publisher
    ..Functional differences appear to exist even among rodent ears of the same general type, but the adaptive significance of these differences remains enigmatic...
  8. Jaryszak E, Sampson E, Antonelli P. Biofilm formation by Pseudomonas aeruginosa on ossicular reconstruction prostheses. Am J Otolaryngol. 2009;30:367-70 pubmed publisher
    ..The purpose of this experiment was to determine if PA forms biofilm on different ossicular chain reconstruction prostheses to a different degree...
  9. Jeng F, Tsai M, Brown C. Relationship of preoperative findings and ossicular discontinuity in chronic otitis media. Otol Neurotol. 2003;24:29-32 pubmed
    ..If preoperative information can be used to determine whether or not the ossicular chain is intact, the patient can be better informed and the surgeon can be better prepared before surgery...
  10. Xing F, Cao K. [Clinical study of congenital middle ear malformations]. Lin Chuang Er Bi Yan Hou Ke Za Zhi. 2004;18:586-9 pubmed
    ..To search into the diagnosis and treatment of congenital malformation of middle ear...
  11. Weon Y, Kim J, Choi S, Koo J. Bilateral duplication of the internal auditory canal. Pediatr Radiol. 2007;37:1047-9 pubmed
    ..We report bilateral duplication of the internal auditory canal in a 28-month-old boy with developmental delay and sensorineural hearing loss...
  12. Rodriguez Vazquez J. Development of the stapes and associated structures in human embryos. J Anat. 2005;207:165-73 pubmed
    ..According to the results, the otic capsule is not involved in formation of the base of the stapes...
  13. Neudert M, Zahnert T, Lasurashvili N, Bornitz M, Lavcheva Z, Offergeld C. Partial ossicular reconstruction: comparison of three different prostheses in clinical and experimental studies. Otol Neurotol. 2009;30:332-8 pubmed publisher
    ..To compare the reconstruction results of a long incus process defect using 3 different partial ossicular replacement prostheses (PORP)...
  14. Kanzaki S, Ito M, Takada Y, Ogawa K, Matsuo K. Resorption of auditory ossicles and hearing loss in mice lacking osteoprotegerin. Bone. 2006;39:414-9 pubmed
    ..These data suggest that osteoprotegerin plays a crucial role in hearing by protecting the auditory ossicles and otic capsule from osteoclastic bone resorption...
  15. Stieve M, Hedrich H, Battmer R, Behrens P, Muller P, Lenarz T. Experimental middle ear surgery in rabbits: a new approach for reconstructing the ossicular chain. Lab Anim. 2009;43:198-204 pubmed publisher
    ..The conductive hearing threshold was in the range of 4.21 +/- 6.68 dB nHL (n = 131). The hearing level showed no significant difference before and after surgery (P < 0.05)...
  16. Kojima H, Tanaka Y, Shiwa M, Sakurai Y, Moriyama H. Congenital cholesteatoma clinical features and surgical results. Am J Otolaryngol. 2006;27:299-305 pubmed
    ..5% of the patients, so the columella on the foot plate method was most frequently used for ossiculoplasty, followed by the columella on the stapes method and the Wullstein type I method...
  17. Jenkins H, Atkins J, Horlbeck D, Hoffer M, Balough B, Arigo J, et al. U.S. Phase I preliminary results of use of the Otologics MET Fully-Implantable Ossicular Stimulator. Otolaryngol Head Neck Surg. 2007;137:206-12 pubmed
    ..The safety of the Otologics Fully-Implantable MET Ossicular Stimulator was assessed in adult patients with bilateral moderate to severe sensorineural hearing loss...
  18. Horiuchi H, Saito N, Kinoshita T, Wakabayashi S, Tsutsumimoto T, Otsuru S, et al. Enhancement of recombinant human bone morphogenetic protein-2 (rhBMP-2)-induced new bone formation by concurrent treatment with parathyroid hormone and a phosphodiesterase inhibitor, pentoxifylline. J Bone Miner Metab. 2004;22:329-34 pubmed
  19. Skotnicka B, Hassmann Poznańska E. [Clinical and pathological features of cholesteatoma in young children]. Otolaryngol Pol. 2010;64:375-81 pubmed publisher
    ..Children cholesteatoma have been shown to demonstrate aggressive growth with greater extension and higher rates residual and recurrent disease compared with adults, due to anatomic and physiologic differences...
  20. Bloch S. On the biology of the bony otic capsule and the pathogenesis of otosclerosis. Dan Med J. 2012;59:B4524 pubmed
    ..A sustained OPG signal from surrounding osteocyte survivors might distort the process and account for the otosclerotic morphology...
  21. Barmack N, Guo H, Kim H, Qian H, Qian Z. Neuronally modulated transcription of a glycine transporter in rat dorsal cochlear nucleus and nucleus of the medial trapezoid body. J Comp Neurol. 1999;415:175-88 pubmed
    ..in auditory primary afferent activity, caused by either unilateral labyrinthectomy or disruption of the middle ear ossicles, caused a reduction in Glyt2, but not Glyt1 mRNA in the ipsilateral DCN and in the contralateral medial nucleus ..
  22. Kazikdas K, Onal K, Yildirim N. Sensorineural hearing loss after ossicular manipulation and drill-generated acoustic trauma in type I tympanoplasty with and without mastoidectomy: A series of 51 cases. Ear Nose Throat J. 2015;94:378-98 pubmed
  23. Brown J, Torbatian Z, Adamson R, Van Wijhe R, Pennings R, Lockwood G, et al. High-frequency ex vivo ultrasound imaging of the auditory system. Ultrasound Med Biol. 2009;35:1899-907 pubmed publisher
    ..These images demonstrate that high-frequency ultrasound imaging of the middle and inner ear can provide valuable diagnostic information using minimally invasive techniques that could potentially be implemented in vivo...
  24. Martin C, Oletski A, Prades J. Surgery of idiopathic malleus fixation. Otol Neurotol. 2009;30:165-9 pubmed
    ..To describe and compare 2 different surgical techniques used in treatment of malleus fixation syndrome...
  25. Huttenbrink K, Luers J, Beutner D. Titanium angular clip: a new prosthesis for reconstruction of the long process of the incus. Otol Neurotol. 2009;30:1186-90 pubmed publisher
    ..To describe a new titanium angular clip prosthesis for bridging the incudostapedial joint in the event of an isolated lesion of the distal end of the long process of the incus...
  26. Morioka S, Sakaguchi H, Taki M, Hyogo M, Suzuki T, Hisa Y. [Congenital ossicular malformation: a study of 27 ears]. Nihon Jibiinkoka Gakkai Kaiho. 2010;113:790-7 pubmed
    ..We discuss problems and solutions using a malleus attachment piston or prosthesis, preoperative audio-and radiological findings, and operative findings including facial nerve anomaly and congenital cholesteatoma...
  27. Wiatr M, Oles K, Tomik J, Składzień J, Morawska A, Strek P, et al. [Prognostic factors in patients operated on eardrum perforation with intact ossicular chain]. Otolaryngol Pol. 2011;65:266-71 pubmed publisher
    ..Ear drum perforation is a typical feature in chronic otitis media. It can have posttraumatic etiology or it is observed in acute otitis media too...
  28. Xu X, Jiang Z, Ma H, Yan D, Chen X, Xu Y, et al. [The study between temporal bone HRCT and operations in congenital abnormality of external and middle ear]. Lin Chung Er Bi Yan Hou Tou Jing Wai Ke Za Zhi. 2013;27:355-8 pubmed
  29. Barbosa V, Santos M, Becker H, Diniz R. Osteoma of the middle ear. Braz J Otorhinolaryngol. 2007;73:719 pubmed
  30. Truy E, Naiman A, Pavillon C, Abedipour D, Lina Granade G, Rabilloud M. Hydroxyapatite versus titanium ossiculoplasty. Otol Neurotol. 2007;28:492-8 pubmed
    ..To compare the results of ossicular chain reconstruction using hydroxyapatite (HA) and titanium (TI) prostheses...
  31. Karosi T, Konya J, Szabó L, Sziklai I. Measles virus prevalence in otosclerotic foci. Adv Otorhinolaryngol. 2007;65:93-106 pubmed
    ..The etiologic role of measles virus in the pathogenesis of otosclerosis should be considered. The 40 negative samples may be genetically determined otosclerotic cases or stapes fixations due to other causes...
  32. Yung M, Vowler S. Long-term results in ossiculoplasty: an analysis of prognostic factors. Otol Neurotol. 2006;27:874-81 pubmed
    ..The aim of the present study is to examine the prognostic factors based on 6-month and 5-year results of ossiculoplasty...
  33. Daneshi A, Shafeghati Y, Karimi Nejad M, Khosravi A, Farhang F. Hereditary bilateral conductive hearing loss caused by total loss of ossicles: a report of familial expansile osteolysis. Otol Neurotol. 2005;26:237-40 pubmed
    The objective of this study was to report on three members of a family with familial expansile osteolysis; the important point about these patients was that none of them had middle-ear ossicles.
  34. el Bitar M, Choi S, Emamian S, Vezina L. Congenital middle ear cholesteatoma: need for early recognition--role of computed tomography scan. Int J Pediatr Otorhinolaryngol. 2003;67:231-5 pubmed
    ..There is controversy regarding the best way to delineate CC preoperatively. More specifically, the need to obtain preoperative computed tomography (CT) scan in all cases of CC is debated...
  35. Turcanu D, Mârţu D, Dalhoff E, Gummer A. [Laser Doppler vibrometry: a new tool for diagnosing hearing loss with an intact eardrum]. Rev Med Chir Soc Med Nat Iasi. 2006;110:357-66 pubmed
    ..Called "laser-audiometry", the method promises to become a new diagnostic tool for hearing impairment...
  36. Hoth S, Lohaus M, Waldmann B. [Auditory brainstem responses evoked by direct mechanical stimulation of the ossicular chain. Objective preoperative testing of candidates for implantable hearing aids]. HNO. 2003;51:550-7 pubmed
    ..In special cases, it could be desirable to perform objective testing before implantation. We therefore studied the auditory brainstem responses (ABR) evoked by vibratory stimulation of the ear drum...
  37. Silverstein H, Jackson L, Conlon W, Rosenberg S, Thompson Jr J. Laser stapedotomy minus prosthesis (laser STAMP): absence of refixation. Otol Neurotol. 2002;23:152-7 pubmed
    ..To determine what percentage of patients with otosclerosis could successfully undergo a laser stapedotomy minus prosthesis over a 5-year period, and to determine the percentage of patients in whom refixation develops during follow-up...
  38. Sienknecht U. Developmental origin and fate of middle ear structures. Hear Res. 2013;301:19-26 pubmed publisher
    ..Middle ear ossicles and other skeletal elements of the viscerocranium (i.e...
  39. Chhan D, Roosli C, McKinnon M, Rosowski J. Evidence of inner ear contribution in bone conduction in chinchilla. Hear Res. 2013;301:66-71 pubmed publisher
    ..g., cochlear fluid inertia or compressibility) to the BC response. This article is part of a special issue entitled "MEMRO 2012"...
  40. Schmidt J, Cole T, Silcox M. Technical note: a landmark-based approach to the study of the ear ossicles using ultra-high-resolution X-ray computed tomography data. Am J Phys Anthropol. 2011;145:665-71 pubmed publisher
    Previous study of the ear ossicles in Primates has demonstrated that they vary on both functional and phylogenetic bases. Such studies have generally employed two-dimensional linear measurements rather than three-dimensional data...
  41. Uslu C, Tek A, Tatlipinar A, Kiliçarslan Y, Durmus R, Ayöğredik E, et al. Cartilage reinforcement tympanoplasty: otological and audiological results. Acta Otolaryngol. 2010;130:375-83 pubmed publisher
    ..High risk perforations including total, subtotal, atelectatic perforations, those with cholesteatoma and revision cases can be treated efficiently with cartilage reinforcement tympanoplasty...
  42. Parent P, Allen J. Time-domain "wave" model of the human tympanic membrane. Hear Res. 2010;263:152-67 pubmed publisher
    ..Besides, model predictions reveal that impedance and velocimetry measurements may be inconsistent with each other, hypothetically because velocimetry protocols could alter the middle ear...
  43. Ramirez Aristeguieta L, Ballesteros Acuña L, Sandoval Ortiz G. [Tensor veli palatini and tensor tympani muscles: anatomical, functional and symptomatic links]. Acta Otorrinolaringol Esp. 2010;61:26-33 pubmed publisher
    ..We seek to demonstrate and explain this connection through the morphometry of these structures...
  44. Ji Q, Luo Z, Zhang X, Yuan C, Xu L. Evolutionary development of the middle ear in Mesozoic therian mammals. Science. 2009;326:278-81 pubmed publisher
    ..Reabsorption of embryonic Meckel's cartilage to disconnect the ear ossicles from the mandible is patterned by a network of genes and signaling pathways...
  45. Kanzaki S, Inoue Y, Watabe T, Ogawa K. Hypertrophic chronic pachymeningitis associated with chronic otitis media and mastoiditis. Auris Nasus Larynx. 2004;31:155-9 pubmed
    ..We speculate that removal of the infectious granulation within the middle ears and mastoids ameliorated the acute inflammation. The etiology remains unknown in this case...
  46. Amin S, Tucker A. Joint formation in the middle ear: lessons from the mouse and guinea pig. Dev Dyn. 2006;235:1326-33 pubmed
    ..The malleal-incudo complex in the guinea pig is, therefore, not caused by a defect in joint initiation...
  47. Yamashita K, Yoshiura T, Hiwatashi A, Kamano H, Honda H. Ultrashort echo time imaging of normal middle ear ossicles: a feasibility study. Dentomaxillofac Radiol. 2012;41:601-4 pubmed publisher
    The aim of this study was to assess the feasibility of ultrashort echo time (UTE) imaging in the visualization of middle ear ossicles in normal subjects.
  48. Qvist M, Grøntved A. Chronic otitis media sequelae in skeletal material from medieval Denmark. Laryngoscope. 2001;111:114-8 pubmed
    ..COMS reflecting episodes of upper respiratory tract infection may be used as a paleopathological indicator of general health. Estimation of the frequency of COMS may be useful in the gross evaluation of general standard of living...
  49. Murakami S, Gyo K, Goode R. Effect of middle ear pressure change on middle ear mechanics. Acta Otolaryngol. 1997;117:390-5 pubmed
    ..These effects were thought to be primarily due to an increased stiffness of the TM and a damping of ossicular vibration, due to stretching of the ossicular suspensory ligaments and the annular ligament of the footplate...
  50. Stankovic M. Audiologic results of surgery for cholesteatoma: short- and long-term follow-up of influential factors. Otol Neurotol. 2008;29:933-40 pubmed publisher
    ..To review the audiologic results in a cohort of patients surgically treated for cholesteatoma...
  51. Gerard J, Cailliau A, Franceschi D, Gersdorff M. [Ossiculoplasty with hydroxyapatite bone cement]. Rev Laryngol Otol Rhinol (Bord). 2012;133:67-70 pubmed
    ..To analyze the results obtained with hydroxyapatite bone cement (HABC)...
  52. Whyte J, Gonzalez L, Cisneros A, Yus C, Torres A, Sarrat R. Fetal development of the human tympanic ossicular chain articulations. Cells Tissues Organs. 2002;171:241-9 pubmed
    ..To obtain further knowledge on the morphogenesis of the articulations in the tympanic ossicular chain in humans...
  53. Chen B, Tao D. [Efficacy of ossicular chain reconstruction using titanium implants in single-stage tympanoplasty]. Zhonghua Er Bi Yan Hou Tou Jing Wai Ke Za Zhi. 2012;47:270-3 pubmed
    ..To explore the efficacy of total and partial ossicular chain reconstruction using titanium implants...
  54. Pauriol Lacaze S, Pouget J, Michel F, Martin C, Veyret C. [Advantage of virtual endoscopy in the evaluation of the ossicular chain]. J Radiol. 2003;84:1961-8 pubmed
    ..Our study consists of a comparison of traditional computed tomography (CT) data sets with 2 views of virtual endoscopy in the preoperative evaluation of various diseases of the middle ear...
  55. Visvanathan V, Kubba H, Morrissey M. Cholesteatoma surgery in children: 10-year retrospective review. J Laryngol Otol. 2012;126:450-3 pubmed publisher
    ..To review outcomes following paediatric cholesteatoma surgery performed between 1999 and 2009 in a tertiary paediatric ENT unit...
  56. Yao W, Li B, Huang X, Guo C, Luo X, Zhou W, et al. Restoring hearing using total ossicular replacement prostheses--analysis of 3D finite element model. Acta Otolaryngol. 2012;132:152-9 pubmed publisher
    ..Also, the best hearing restoration is obtained when the total ossicular replacement prosthesis (TORP) is placed onto the center of the stapes footplate during operation...
  57. Park K, Moon S, Cho M, Won Y, Baek M. 3D micro-CT images of ossicles destroyed by middle ear cholesteatoma. Acta Otolaryngol. 2004;124:403-7 pubmed
    ..To reconstruct the 3D structures of normal ossicles and ossicles destroyed by different cholesteatomas, and to compare the volume fractions of the two types of ossicles...
  58. Menéndez Colino L, Bernal Sprekelsen M. [Tympanic-ossicular reconstruction. Functional results using cartilage palisades and titanium prostheses]. Acta Otorrinolaringol Esp. 2002;53:718-24 pubmed
    ..Seven out of sixteen canal wall down (43.7%) and three out seven canal wall up (42.9%) had a postoperative air-bone gap between 0 and 10 dB...
  59. Deveze A, Koka K, Tringali S, Jenkins H, Tollin D. Techniques to improve the efficiency of a middle ear implant: effect of different methods of coupling to the ossicular chain. Otol Neurotol. 2013;34:158-66 pubmed publisher
    ..Coupling and placement of actuators onto the ossicular chain have a significant influence on active middle ear implant (AMEI) performance...
  60. Whyte Orozco J, Cisneros Gimeno A, Urieta Carpi J, Yus Gotor C, Gañet Solé J, Torres del Puerto A, et al. [Ontogenic peculiarities of the human tympanic ossicular chain]. Acta Otorrinolaringol Esp. 2003;54:1-10 pubmed
  61. Schneider G. [Bioimplants--characteristics and use]. Laryngorhinootologie. 2003;82:839-52; quiz 853-7 pubmed
    ..On the basis of its origin, the infection security plays a large role next to the general demands on an implant. The materials related today and its fields of application are discussed...
  62. Nummela S, Wagar T, Hemila S, Reuter T. Scaling of the cetacean middle ear. Hear Res. 1999;133:71-81 pubmed
    ..The mean ossicular density is 2.64 g/cm3 for odontocetes, and 2.35 g/cm3 for mysticetes. The highly mineralized and convex tympanic plate provides cetaceans with a uniquely large and stiff sound collecting area...