scholarly journals Sound intensity and reflection coefficient measurements in the ear canal

1991 ◽  
Vol 89 (4B) ◽  
pp. 1864-1864
Author(s):  
R. D. Rabbitt ◽  
J. Dragicevic
Keyword(s):  
Reflection Coefficient ◽  
Sound Intensity ◽  
Ear Canal

Ear‐canal impedance and reflection coefficient in human infants and adults

1993 ◽  
Vol 94 (5) ◽  
pp. 2617-2638 ◽  
Author(s):  
Douglas H. Keefe ◽  
Jay C. Bulen ◽  
Kathy Hoberg Arehart ◽  
Edward M. Burns
Keyword(s):  
Reflection Coefficient ◽  
Ear Canal ◽  
Human Infants

scholarly journals A Transfer Matrix Model of the IEC 60318-4 Ear Simulator: Application to the Simulation of Earplug Insertion Loss

2019 ◽  
Vol 105 (6) ◽  
pp. 1258-1268
Author(s):  
Yu Luan ◽  
Franck Sgard ◽  
Simon Benacchio ◽  
Hugues Nélisse ◽  
Olivier Doutres
Keyword(s):  
Transfer Matrix ◽  
Insertion Loss ◽  
Numerical Models ◽  
Sound Intensity ◽  
Lumped Parameter Model ◽  
Reference Plane ◽  
Fe Model ◽  
Ear Canal ◽  
Viscous Effects ◽  
Tm Model

The IEC 60318-4 ear simulator is used to measure the insertion loss (IL) of earplugs in the ear canal of an acoustical test fixture (ATF) and is designed to represent an average acoustic impedance (in a reference plane) of the human ear. The ear simulator is usually modeled using a lumped parameter model (LPM) which has frequency limitations and inadequately accounts for the thermo-viscous effects in the simulator. The simulator numerical models that can better deal with the thermo-viscous phenomena often lack essential geometric details. Most related studies also suffer from the lack of experimental validation of the models. Therefore, a transfer matrix (TM) model of the IEC 60318-4 simulator is proposed based on a direct assessment of its geometric dimensions. Such a model is of particular interest for designing artificial ear simulators. The variability in the simulator impedance due to the geometric uncertainties is quantified using the Monte Carlo method. The TM model is validated using i) a finite element (FE) model of the simulator and ii) impedance measurements with a sound intensity probe. It is found to better describe the simulator impedance above 3 kHz compared to the LPM. The TM model is then coupled to a FE model of an occluded ATF ear canal to simulate the IL of an earplug in the frequency range [100 Hz, 10 kHz]. In the model, the simulator is considered as a cylindrical cavity terminated by an equivalent tympanic impedance which is determined from the TM model to simulate the sound pressure measured at the real microphone position (not at the reference plane) in the ATF ear canal. The simulated IL is validated against i) that obtained with a complete FE model of the corresponding system and ii) measurements using an ATF. The TM model is shown to better agree with the simulator FE model than the LPM above 6 kHz regarding the earplug IL simulated using this method.

Anatomical Study of the Modified Glasscock Approach with a Temporary Removal of the Bony Ear Canal

Skull Base ◽  
2007 ◽  
Vol 17 (S 1) ◽  
Author(s):  
H. Kunst ◽  
J. Lavieille ◽  
A. Devèze ◽  
K. Graamans ◽  
J. Magnan
Keyword(s):  
Anatomical Study ◽  
Ear Canal
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