Spatial Distribution of Sound Pressure in the Ear Canal

1986 ◽  
pp. 13-20 ◽  
Author(s):  
Michael R. Stinson
Keyword(s):  
Spatial Distribution ◽  
Sound Pressure ◽  
Ear Canal

The spatial distribution of sound pressure within the human ear canal

2005 ◽  
Vol 117 (4) ◽  
pp. 2564-2564
Author(s):  
Michael R. Stinson ◽  
Gilles A. Daigle
Keyword(s):  
Spatial Distribution ◽  
Sound Pressure ◽  
Ear Canal ◽  
Human Ear

The Occlusion Effect in Bone Conduction Hearing

1965 ◽  
Vol 8 (2) ◽  
pp. 137-148 ◽  
Author(s):  
David P. Goldstein ◽  
Claude S. Hayes
Keyword(s):  
Sound Pressure Level ◽  
Sound Pressure ◽  
Bone Conduction ◽  
Pressure Level ◽  
Ear Canal ◽  
Significant Difference ◽  
Threshold Measure ◽  
Level Shifts ◽  
Positive Correlations ◽  
Occlusion Effect

This experiment tested the hypothesis that the occlusion effect is accompanied by an increase in sound pressure level in the external auditory canal. Pure tone bone conduction thresholds and sound pressure levels were measured, first with the ear canal open, then with the ear canal closed, at two positions of the bone vibrator and at five frequencies in 28 normal listeners. Statistical analyses revealed a significant difference between measures at 250, 500, and 1 000 cps but not at 2 000 and 4 000 cps. Average sound pressure level shifts tended to be larger than their threshold measure counterparts. The two measures, nevertheless, yielded positive correlations.

Probe-Tube Microphone Measures of Ear-Canal Sound Pressure Levels in Infants and Children

1989 ◽  
Vol 10 (4) ◽  
pp. 254-258 ◽  
Author(s):  
Judith A. Feigin ◽  
Judy G. Kopun ◽  
Patricia G. Stelmachowicz ◽  
Michael P. Gorga
Keyword(s):  
Sound Pressure ◽  
Infants And Children ◽  
Ear Canal ◽  
Sound Pressure Levels ◽  
In Infants And Children

Spatial distribution of sound pressure and energy flow in the ear canals of cats

1994 ◽  
Vol 96 (1) ◽  
pp. 170-180 ◽  
Author(s):  
Michael R. Stinson ◽  
Shyam M. Khanna
Keyword(s):  
Spatial Distribution ◽  
Energy Flow ◽  
Sound Pressure ◽  
Ear Canals

scholarly journals Protective earphones and human hearing system response to the received sound frequency signals

2018 ◽  
Vol 37 (4) ◽  
pp. 1030-1036 ◽  
Author(s):  
Niloofar Ziayi Ghahnavieh ◽  
Siamak Pourabdian ◽  
Farhad Forouharmajd
Keyword(s):  
Hearing Loss ◽  
Noise Reduction ◽  
Sound Pressure ◽  
Pressure Sensors ◽  
Sound Level ◽  
System Response ◽  
Ear Canal ◽  
Labview Software ◽  
Negative Effect ◽  
Sound Reduction

Sound is one of the most important problems in industrial environments, and it causes hearing loss at different frequencies in the workforce. Incorrect fitting of hearing protector has a negative effect on noise reduction. The present study was conducted with the aim of determination of the effective frequencies on hearing loss and variations of the sound level in different frequencies after placing the earplug. A model of ear canal with different materials was simulated. Sound pressure sensors and earplugs were placed in both sides of the ear canal. The rates of sound reduction in octave frequency signals were calculated for the simulated canal of different materials, in different distances between the microphone and the earplug with Labview software. The results of sound simulation in octave frequency signals showed that by increasing the frequency, the rates of sound reduction in different conditions also had an increasing trend. The obtained peak rates for all the situations coincided with each other at fixed frequencies. In most cases, a noise reduction in the frequency of 4000 Hz showed a high number. The maximum sound reduction was observed at 25.5 mm at frequencies below 250 Hz, which was similar to the average of human ear canal length; so the simulated model can be used to determine the performance of the protective earphones and test them at different frequencies and sound pressure levels.

Transverse variations of sound pressure in an ear canal occluded by a hearing aid

2006 ◽  
Vol 120 (5) ◽  
pp. 3159-3159
Author(s):  
Michael R. Stinson ◽  
Gilles A. Daigle
Keyword(s):  
Sound Pressure ◽  
Hearing Aid ◽  
Ear Canal

Using Average Correction Factors to Improve the Estimated Sound Pressure Level Near the Tympanic Membrane

2012 ◽  
Vol 23 (09) ◽  
pp. 733-750
Author(s):  
Karrie LaRae Recker ◽  
Tao Zhang ◽  
Weili Lin
Keyword(s):  
Tympanic Membrane ◽  
Sound Pressure Level ◽  
Hearing Aids ◽  
Best Practice ◽  
Sound Pressure ◽  
Pressure Level ◽  
Correction Factors ◽  
Ear Canal ◽  
Frequency Components ◽  
Ear Canals

Background: Sound pressure-based real ear measurements are considered best practice for ensuring audibility among individuals fitting hearing aids. The accuracy of current methods is generally considered clinically acceptable for frequencies up to about 4 kHz. Recent interest in the potential benefits of higher frequencies has brought about a need for an improved, and clinically feasible, method of ensuring audibility for higher frequencies. Purpose: To determine whether (and the extent to which) average correction factors could be used to improve the estimated high-frequency sound pressure level (SPL) near the tympanic membrane (TM). Research Design: For each participant, real ear measurements were made along the ear canal, at 2–16 mm from the TM, in 2-mm increments. Custom in-ear monitors were used to present a stimulus with frequency components up to 16 kHz. Study Sample: Twenty adults with normal middle-ear function participated in this study. Intervention: Two methods of creating and implementing correction factors were tested. Data Collection and Analysis: For Method 1, correction factors were generated by normalizing all of the measured responses along the ear canal to the 2-mm response. From each normalized response, the frequency of the pressure minimum was determined. This frequency was used to estimate the distance to the TM, based on the ¼ wavelength of that frequency. All of the normalized responses with similar estimated distances to the TM were grouped and averaged. The inverse of these responses served as correction factors. To apply the correction factors, the only required information was the frequency of the pressure minimum. Method 2 attempted to, at least partially, account for individual differences in TM impedance, by taking into consideration the frequency and the width of the pressure minimum. Because of the strong correlation between a pressure minimum's width and depth, this method effectively resulted in a group of average normalized responses with different pressure-minimum depths. The inverse of these responses served as correction factors. To apply the correction factors, it was necessary to know both the frequency and the width of the pressure minimum. For both methods, the correction factors were generated using measurements from one group of ten individuals and verified using measurements from a second group of ten individuals. Results: Applying the correction factors resulted in significant improvements in the estimated SPL near the TM for both methods. Method 2 had the best accuracy. For frequencies up to 10 kHz, 95% of measurements had <8 dB of error, which is comparable to the accuracy of real ear measurement methods that are currently used clinically below 4 kHz. Conclusions: Average correction factors can be successfully applied to measurements made along the ear canals of otologically healthy adults, to improve the accuracy of the estimated SPL near the TM in the high frequencies. Further testing is necessary to determine whether these correction factors are appropriate for pediatrics or individuals with conductive hearing losses.

Sound Pressure in Insert Earphone Couplers and Real Ears

1977 ◽  
Vol 20 (4) ◽  
pp. 799-807 ◽  
Author(s):  
M. D. Burkhard ◽  
R. M. Sachs
Keyword(s):  
Frequency Response ◽  
Experimental Verification ◽  
Cylindrical Cavity ◽  
Sound Pressure ◽  
Single Frequency ◽  
Ear Canal ◽  
Circular Symmetry ◽  
Transfer Impedance ◽  
Volume Velocity ◽  
Main Cavity

It is known that sound pressure, measured in couplers via a probe-tube microphone, often shows a pressure vs frequency response that drops sharply at a single frequency. In this study sound pressure was theoretically determined at various locations within a hard-walled cylindrical cavity, driven by a constant-volume velocity source with circular symmetry. At each location in the volume, a transfer impedance was defined as the ratio of pressure to inlet-volume velocity. In the region around the inlet, the transfer impedance passes through zero as it changes from negative to positive reactance with increasing frequency. Two hard-walled cavity examples were examined in detail (1) the main cavity of a 2-cm 3 HA-2 coupler, and (2) a cavity having dimensions approximately equal to the occluded ear canal between an earmold tip and the eardrum. Contours of constant minimum sound pressure vs frequency are given for these two cylindrical volumes with experimental verification. Implications for probe microphone calibration and measurement of sound pressure in ears are discussed.

scholarly journals Estimation of bone conduction skull transmission by hearing thresholds and ear-canal sound pressure

2013 ◽  
Vol 299 ◽  
pp. 19-28 ◽  
Author(s):  
Sabine Reinfeldt ◽  
Stefan Stenfelt ◽  
Bo Håkansson
Keyword(s):  
Sound Pressure ◽  
Bone Conduction ◽  
Ear Canal ◽  
Hearing Thresholds
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