Hearing Aid Saturation and Aided Loudness Discomfort

1992 ◽  
Vol 35 (1) ◽  
pp. 175-185 ◽  
Author(s):  
Todd W. Fortune ◽  
David A. Preves
Keyword(s):  
Sound Pressure Level ◽  
Hearing Aids ◽  
Sound Pressure ◽  
Hearing Aid ◽  
Significant Negative Correlation ◽  
Sound Quality ◽  
Pressure Level ◽  
The Subject ◽  
Clinical Measurements

Clinical measurements of the loudness discomfort level (LDL) are generally performed while the subject listens to a particular stimulus presented from an audiometer through headphones (AUD-HP). The assumption in clinical practice has been that the sound pressure level (SPL) corresponding to the sensation of loudness discomfort under AUD-HP conditions will be the same as that corresponding to LDL with the hearing aid. This assumption ignores the fact that the distortion produced by a saturating hearing aid could have an influence on the sensation of loudness. To examine these issues, 5 hearing-impaired subjects were each fit with four linear hearing aids, each having a different saturation sound pressure level (SSPL90). Probe-tube microphone measurements of ear canal SPL at LDL were made while the subjects listened to continuous discourse in quiet under aided and AUD-HP conditions. Also using continuous discourse, real-ear coherence measures were made at various output sound pressure levels near LDL. All four hearing aid types produced mean LDLs that were lower than those obtained under AUD-HP conditions. Those hearing aids with higher SSPL90 produced significantly higher LDLs than hearing aids with lower SSPL90. A significant negative correlation was found between real-ear SPL and real-ear coherence. Quality judgments made at LDL indicated that sound quality of hearing aids with higher SSPL90 was preferred to that of hearing aids with lower SSPL90. Possible fitting implications regarding the setting of SSPL90 from AUD-HP LDL measures are discussed.

scholarly journals Speech and Sound Quality Recognition in Adults Bimodal Cochlear Implant Listeners

2021 ◽  
Vol 17 (2) ◽  
pp. 198-205
Author(s):  
Leehwa Park ◽  
Soo Hee Oh
Keyword(s):  
Cochlear Implant ◽  
Sound Pressure ◽  
Hearing Aid ◽  
Sound Quality ◽  
Pressure Level ◽  
Story Comprehension ◽  
Monosyllabic Word ◽  
Quality Dimensions ◽  
Basic Evaluation

Purpose: Recent bimodal studies identified a lack of bimodal evaluation and fitting protocols to improve bimodal benefits. The purpose of this study is to measure bimodal benefits in speech and sound quality recognition and identify bimodal fitting issues with adult cochlear implant listeners to establish bimodal fitting guidelines and evaluation protocol.Methods: A total of 20 adult cochlear implant users were participated in this study. The experimental procedures included basic evaluation, hearing aid evaluation, and bimodal benefits evaluation. In order to evaluate bimodal benefits, speech and sound quality recognition tests were performed. Matrix sentences in quiet and noise (5 and 10 dB sound pressure level), consonant-vowel-consonant words, and story comprehension tasks were provided. Participants judged sound qualities for six sound quality dimensions and a tester performed real ear measurements to verify hearing aid gains.Results: Results showed that bimodal listeners had some bimodal benefits in the sentence and monosyllabic word recognition in quiet. The benefits of sound quality judgments were also observed for six sound quality dimensions. Bimodal cochlear implant listeners of this study demonstrated less real-ear insertion gains than target gains across test frequencies.Conclusion: Speech and sound quality recognition tests are useful tools to measure bimodal benefits. Additional care for bimodal listeners is needed to optimize bimodal fitting and improve the quality of bimodal hearing aid fitting services.

Numerical Analysis of the Acoustical Quality of a Multi-Purpose Hall

1995 ◽  
Vol 2 (3) ◽  
pp. 487-500 ◽  
Author(s):  
X.W. Meng ◽  
G. De Borger ◽  
M. Van Overmeire
Keyword(s):  
Computer Simulation ◽  
Sound Pressure Level ◽  
Decay Time ◽  
Sound Pressure ◽  
Field Measurements ◽  
Pressure Level ◽  
Energy Fraction ◽  
Experimental Values ◽  
Simulation Package

In this paper, the acoustical features are described of a multi-purpose auditorium of the Free University of Brussels which were investigated both with field measurements and computer simulation. The convergence of the algorithm of the simulation package RAYNOISE was investigated as a function of the influence on the calculated results of the choice of the number of rays and the reflection order. By comparing the numerical and experimental values of the sound pressure level and early decay time, it is demonstrated that sufficiently accurate acoustical models can be developed. Based on these models, acoustical quantities such as the early energy fraction, sound pressure level, early decay time and early lateral energy fraction were calculated and employed to evaluate the acoustical quality of this multi-purpose hall.

Temporary Threshold Shift from a Toy Cap Gun

1974 ◽  
Vol 39 (2) ◽  
pp. 163-168 ◽  
Author(s):  
Lynne Marshall ◽  
John F. Brandt
Keyword(s):  
Hearing Loss ◽  
Sound Pressure Level ◽  
Sound Pressure ◽  
Noise Exposure ◽  
Pressure Level ◽  
Threshold Shift ◽  
Temporary Threshold Shift ◽  
Fixed Frequency ◽  
Before And After ◽  
The Subject

Temporary threshold shift resulting from exposure to one and five toy cap gun pistol shots was investigated using 11 normal-hearing adult subjects and one subject with a noise-induced hearing loss. The subjects fired the cap gun at arm’s length, and absolute thresholds at 4000 Hz were obtained before and after noise exposure by a fixed-frequency Bekesy technique. After exposure to one gunshot, five subjects showed a small TTS, five demonstrated no TTS, and two (including the subject with the hearing loss) exhibited negative TTS. No TTS occurred in any of the subjects after exposure to five shots. It was postulated that the small amount of TTS was due to the unexpectedly low sound pressure level produced by the cap gun and to the contraction of the middle ear muscles in some subjects prior to firing.

A comparison of two methods for estimating sound pressure level at the tympanic membrane at high frequencies for hearing aids.

2010 ◽  
Vol 127 (3) ◽  
pp. 1868-1868
Author(s):  
Tao Zhang ◽  
Karrie Recker ◽  
Janice LoPresti ◽  
Matt Kleffner ◽  
William Ryan
Keyword(s):  
Tympanic Membrane ◽  
Sound Pressure Level ◽  
Hearing Aids ◽  
Sound Pressure ◽  
Pressure Level ◽  
High Frequencies

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.

Control of hearing-aid saturated sound pressure level by frequency-shaped output compression limiting

1999 ◽  
Vol 28 (1) ◽  
pp. 27-38 ◽  
Author(s):  
Hugh J. McDermott ◽  
Michelle R. Dean ◽  
Harvey Dillon
Keyword(s):  
Sound Pressure Level ◽  
Sound Pressure ◽  
Hearing Aid ◽  
Pressure Level

scholarly journals Evaluation and Improvement of the Sound Quality of a Diesel Engine Based on Tests and Simulations

Energies ◽  
2020 ◽  
Vol 13 (4) ◽  
pp. 777 ◽  
Author(s):  
Zhengwei Yang ◽  
Huihua Feng ◽  
Bingjie Ma ◽  
Ammar Abdualrahim Alnor Khalifa
Keyword(s):  
Diesel Engine ◽  
Sound Pressure Level ◽  
Sound Pressure ◽  
Subjective Evaluation ◽  
Sound Field ◽  
Sound Quality ◽  
Pressure Level ◽  
Sound Power ◽  
Improvement Strategy ◽  
Radiated Sound

Traditional acoustic evaluation of a diesel engine generally uses the A-weighted sound pressure level (AWSPL) and radiated sound power to assess the noise of an engine prototype present in an experiment. However, this cannot accurately and comprehensively reflect the auditory senses of human subjects during the simulation stage. To overcome such shortage, the Moore–Glasberg loudness and sharpness approach is applied to evaluate and improve the sound quality (SQ) of a 16 V-type marine diesel engine, and synthesizing noise audio files. Through finite element (FE) simulations, the modes of the engine’s block and the average vibrational velocity of the entire engine surface were calculated and compared with the test results. By further applying an automatically matched layer (AML) approach, the engine-radiated sound pressure level (SPL) and sound power contributions of all engine parts were obtained. By analyzing the Moore–Glasberg loudness and sharpness characteristics of three critical sound field points, an improvement strategy of the oil sump was then proposed. After improvement, both the loudness and sharpness decreased significantly. To verify the objective SQ evaluation results, ten noise audio clips of the diesel engine were then synthesized and tested. The subjective evaluation results were in accordance with the simulated analysis. Therefore, the proposed approach to analyze and improve the SQ of a diesel engine is reliable and effective.

scholarly journals Analysis and Development of Hybrid Earphone Combining Balanced-Armature and Dynamic Receivers

2019 ◽  
Vol 9 (23) ◽  
pp. 5047
Author(s):  
Yuan-Wu Jiang ◽  
Dan-Ping Xu ◽  
Zhi-Xiong Jiang ◽  
Jun-Hyung Kim ◽  
Sang-Moon Hwang
Keyword(s):  
Frequency Response ◽  
Root Mean Square ◽  
Sound Pressure Level ◽  
Sound Pressure ◽  
Sound Quality ◽  
Pressure Level ◽  
Analysis Tool ◽  
Mean Square ◽  
Rapid Progress ◽  
Audio Output

With the rapid progress in the development of multimedia devices, earphones have become increasingly important as audio output tools. Hybrid earphones combining balanced-armature (BA) and dynamic receivers can produce better performance over a wider range when compared to the earphones with BA receiver alone (BA earphones) or dynamic receiver alone (dynamic earphones). BA and dynamic earphones are multi-physics products that exhibit coupling between the electromagnetic, mechanical, and acoustic domains. In this study, an analysis tool is developed to design a hybrid earphone based on the conventional BA and dynamic earphones. Using the developed analysis tool, an acoustic tube is optimized to match the earphone target curve and obtain improved sound quality. A prototype is manufactured and tested, and the experimental results verify the feasibility and effectiveness of the developed analysis tool. The root-mean-square value of the sound pressure level (SPL) deviation of the hybrid earphone with the optimized acoustic tube is 4.60, whereas those for the dynamic and BA earphones are 8.94 and 6.04, respectively. Thus, it is verified that the frequency response is improved using the hybrid earphone developed herein.

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