Search PubMed⌕ Search
Home/Archive/PubMed

PubMed · 1629475

Occluded-ear simulator with variable acoustic properties.

D P Egolf·W A Kennedy·V D Larson
View original source ↗Export metadata ↓

Abstract

Ear simulators were designed to replicate acoustical characteristics of the average adult ear. Due to variability of ear-canal geometry and eardrum impedance among individuals, the possibility of any one person exhibiting such "average" characteristics--especially if that person is a child and/or has a conductive pathology--is remote. Thus, ear simulators have been of only peripheral value when prescribing a hearing aid (a high output impedance device) to fit the acoustical requirements of a particular patient. Reported herein is development of a programmable artificial ear (PAE) that can account for individual differences in ear-canal geometry and eardrum impedance. It consists of a 2.0-cc coupler, microphone, amplifier, computer, PAE code, and a computer card and/or software for digitization and Fourier transformation. Required input data includes ear-canal dimensions, eardrum impedance, and output impedance of the hearing aid being tested. Sound-pressure recordings produced in the 2.0-cc coupler by the hearing aid are adjusted by the computer to what they would have been had the recordings been made at the eardrum of a particular patient wearing the same hearing aid. Good agreement was observed between experiment and theory for one test case involving a totally occluding miniature earphone.

Explore related subjects

Acoustic Impedance TestsAcousticsEarEar CanalElectronics, MedicalHearing AidsHumansMaterials TestingModels, BiologicalPressureSignal Processing, Computer-AssistedSoftwareSoundJournal ArticleResearch Support, U.S. Gov't, Non-P.H.S.

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

D P Egolf, W A Kennedy, V D Larson. 1992. Occluded-ear simulator with variable acoustic properties.. https://doi.org/10.1121/1.402962

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

PubMed2007

Bayesian estimation of intervention effect with pre- and post-misclassified binomial data.

We consider studies in which an enrolled subject tests positive on a fallible test. After an intervention, disease status is re-diagnosed with the same fallible instrument. Potential misclassification in the diagnostic test causes regression to the mean that biases inferences about the true intervention effect. The existing likelihood approach suffers in situations where either sensitivity or specificity is near 1. In such cases, common in many diagnostic tests, confidence interval coverage can often be below nominal for the likelihood approach. Another potential drawback of the maximum likelihood estimator (MLE) method is that it requires validation data to eliminate identification problems. We propose a Bayesian approach that offers improved performance in general, but substantially better performance than the MLE method in the realistic case of a highly accurate diagnostic test. We obtain this superior performance using no more information than that employed in the likelihood method. Our approach is also more flexible, doing without validation data if necessary, but accommodating multiple sources of information, if available, thereby systematically eliminating identification problems. We show via a simulation study that our Bayesian approach outperforms the MLE method, especially when the diagnostic test has high sensitivity, specificity, or both. We also consider a real data example for which the diagnostic test specificity is close to 1 (false positive probability close to 0).

Acoustic Impedance Tests↗
PubMed2006

Abnormal electronystagmography in rheumatoid arthritis.

OBJECTIVE: Although sensorineural hearing loss has been widely investigated in those with rheumatoid arthritis, studies assessing the vestibular system in patients with rheumatoid arthritis are limited. The aim of this study was to assess the vestibular system in patients with rheumatoid arthritis. METHODS: The study consisted of 43 patients with rheumatoid arthritis and 30 healthy controls. Otorhinolaryngologic and neurotologic examinations, pure-tone audiometry, impedancemetry, electronystagmography including smooth pursuit, saccade, positional, and caloric tests were performed in all patients with rheumatoid arthritis and in controls. The erythrocyte sedimentation rate, C-reactive protein level, and rheumatoid factor level were evaluated in all patients with rheumatoid arthritis. RESULTS: Audiograms revealed sensorineural hearing loss in 12 patients (27.9%) with rheumatoid arthritis and in two controls (6.6%); the difference was statistically significant (P=.033). In those with rheumatoid arthritis, the results of electronystagmography revealed central abnormalities in nine patients (20.9%), peripheral abnormalities in three (6.9%), and mixed abnormalities in three (6.9%). Smooth pursuit and saccade tracing impairments were significantly higher in patients with rheumatoid arthritis (P>.05). Canal paresis in patients with rheumatoid arthritis were significantly higher than those in the control group (P=.039). No association was found between electronystagmographic abnormalities in patients with rheumatoid arthritis and age, sex, duration of disease, the results of laboratory testing, sensorineural hearing loss, or medication use. CONCLUSION: Our results suggest an association of rheumatoid arthritis with vestibular system dysfunction as well as auditory impairment.

Acoustic Impedance Tests↗
PubMed2006

Reproducibility of sonotubometry as Eustachian tube ventilatory function test in healthy children.

OBJECTIVES: To devise a simple and reliable diagnostic procedure to test Eustachian tube function routinely in an ENT outpatient setting. One method to measure ET ventilatory function is sonotubometry. The reproducibility of a recently updated sonotubometry set-up was tested in healthy children. METHODS: The test population comprised 61 school children aged from 6 to 8 years. Only otologically healthy children were included. Health state was established by means of a 12-item questionnaire. To test reproducibility, sonotubometric testing took place in two sessions of 10 acts of swallowing each. Spearman's coefficient was used to test the correlation between the two sets of measurements. All testing took place at a primary school in a nearby village. RESULTS: Opening of the ET was recorded in at least one of the two measurement sessions in 82% of the children. The first and second sessions were highly correlated, with a Spearman's coefficient of 0.89. CONCLUSIONS: In otologically healthy children, opening of the ET was recorded frequently using the updated sonotubometry set-up. Measurement results had high reproducibility. Therefore, the test forms a useful method to assess ET ventilatory function in otologically healthy children. The performance of this updated version needs to be established in children with otological diseases.

Acoustic Impedance Tests↗