OBJECTIVE: To investigate the significance of tympanic membrane collagen fiber layers in high frequency sound transmission. STUDY DESIGN: Human cadaver temporal bone study. METHODS: Laser Doppler vibrometry was used to measure stapes footplate movement in response to acoustic stimulation. The tympanic membrane was altered by creating a series of slits and applying paper patches to isolate the effects of specifically oriented collagen fibers. Three groups of membrane alterations were evaluated: 1) circumferentially oriented slits involving each quadrant to primarily disrupt radial fibers, made sequentially within superior-anterior, inferior-anterior, inferior-posterior, and superior-posterior quadrants; 2) the same slits made in the reverse order; and 3) radially oriented slits from the umbo to the annulus to primarily disrupt circumferential fibers. For each group, measurements of the middle-ear cavity pressure, ear canal pressure, and stapes velocity were made each time the tympanic membrane was altered. RESULTS: Regardless of the order in which the circumferentially oriented slits were made, there was a consistent decrease in stapes velocity above 4 kHz for the third and fourth cuts compared to the control. The mean decrease in the range of 4 to 12.5 kHz was 11 dB for the third patched slit and 14 dB for the fourth patched slit (P < .01). Radially oriented slits appear to produce smaller effects. CONCLUSIONS: Radial collagen fibers in the tympanic membrane play an important role in the conduction of sound above 4 kHz.
OBJECTIVE: To investigate the significance of tympanic membrane collagen fiber layers in high frequency sound transmission. STUDY DESIGN:Human cadaver temporal bone study. METHODS: Laser Doppler vibrometry was used to measure stapes footplate movement in response to acoustic stimulation. The tympanic membrane was altered by creating a series of slits and applying paper patches to isolate the effects of specifically oriented collagen fibers. Three groups of membrane alterations were evaluated: 1) circumferentially oriented slits involving each quadrant to primarily disrupt radial fibers, made sequentially within superior-anterior, inferior-anterior, inferior-posterior, and superior-posterior quadrants; 2) the same slits made in the reverse order; and 3) radially oriented slits from the umbo to the annulus to primarily disrupt circumferential fibers. For each group, measurements of the middle-ear cavity pressure, ear canal pressure, and stapes velocity were made each time the tympanic membrane was altered. RESULTS: Regardless of the order in which the circumferentially oriented slits were made, there was a consistent decrease in stapes velocity above 4 kHz for the third and fourth cuts compared to the control. The mean decrease in the range of 4 to 12.5 kHz was 11 dB for the third patched slit and 14 dB for the fourth patched slit (P < .01). Radially oriented slits appear to produce smaller effects. CONCLUSIONS: Radial collagen fibers in the tympanic membrane play an important role in the conduction of sound above 4 kHz.
Authors: Danielle R Trakimas; Reuven Ishai; Iman Ghanad; Nicole L Black; Elliott D Kozin; Jeffrey Tao Cheng; Aaron K Remenschneider Journal: Laryngoscope Date: 2018-05-14 Impact factor: 3.325
Authors: Yi Shen; Sharon Leanne Redmond; Bing Mei Teh; Sheng Yan; Yan Wang; Lin Zhou; Charley A Budgeon; Robert Henry Eikelboom; Marcus David Atlas; Rodney James Dilley; Minghao Zheng; Robert Jeffery Marano Journal: Tissue Eng Part A Date: 2012-12-10 Impact factor: 3.845
Authors: Marc D Polanik; Danielle R Trakimas; Nicole L Black; Jeffrey T Cheng; Elliott D Kozin; Aaron K Remenschneider Journal: Otolaryngol Head Neck Surg Date: 2020-02-25 Impact factor: 3.497