Search results for "acoustic emission"
showing 10 items of 56 documents
Damage detection of a hybrid composite laminate aluminum/glass under quasi-static and fatigue loadings by acoustic emission technique
2019
Abstract This paper deals with the characterization by Acoustic Emission technique of damages occurring in a hybrid laminate aluminium/glass during quasi-static and fatigue tests. Indeed, hybrid laminates materials metal/composites are more and more considered in structure, automotive and aerospace designs because of their good mechanical performances and lightness. To understand their damages characteristics, several types of laminates (fiber orientations, number of folds, presence or not of an aluminium sheet) have been tested. The acoustic emission analysis has been realized using statistical multi-parameters methods of data clustering: combination of Principal Components Analysis (PCA) …
Confirmation of PDZD7 as a Nonsyndromic Hearing Loss Gene.
2016
Objective PDZD7 was identified in 2009 in a family with apparent nonsyndromic sensorineural hearing loss. However, subsequent clinical reports have associated PDZD7 with digenic Usher syndrome, the most common cause of deaf-blindness, or as a modifier of retinal disease. No further reports have validated this gene for nonsyndromic hearing loss, intuitively calling correct genotype-phenotype association into question. This report describes a validating second case for biallelic mutations in PDZD7 causing nonsyndromic mild to severe sensorineural hearing loss. It also provides detailed audiometric and ophthalmologic data excluding Usher syndrome in both the present proband (proband 1) and the…
Absence of Early Neuronal Death in the Olivocochlear System Following Acoustic Overstimulation
2015
This study was conducted to examine possible effects of noise trauma on olivocochlear (OC) neurons. Anesthetized rats were exposed to a continuous 10 kHz pure tone at 120 dB sound pressure level for 2 hrs. The effects of treatment were verified by recordings of auditory brainstem response and distortion product otoacoustic emission. Three or 8 days after acoustic trauma, rats received unilateral injections of an aqueous solution of the retrograde neuronal tracer Fluorogold (FG) into the scala tympani to identify OC neurons (OCN). Five days after FG injection, brains were perfusion-fixed, and brainstem sections were cut and analyzed with respect to FG-labeled neurons. We found that, in both …
Cochlear origin of early hearing loss in vestibular schwannoma.
2007
Objective: To test whether early hearing loss (HL) is cochlear in origin in patients with vestibular schwannoma (VS). Study Design: Retrospective case review in an academic tertiary referral center. Methods: A group of 19 VS patients with normal/symmetrical hearing and a group of 20 VS patients with mild HL (threshold at any tested frequency better than 45 dB HL) on the tumor ear side. Differences of the amplitudes of the distortion products of otoacoustic emissions (DPOAEs) between the tumor ear and the nontumor ear were studied at frequencies of 1, 1.4, 2, 2.8, and 4 kHz. The Wilcoxon test was used to compare the ears for both groups and to test for possible differences in tumor size betw…
Increased amplitudes of distortion product otoacoustic emissions in patients with unilateral acoustic neuroma.
2004
We present a case series of 4 patients with a unilateral acoustic neuroma and increased amplitudes of the distortion products of otoacoustic emissions (DPOAEs) at the low- and middle- frequency bandwidth on the involved side compared to the uninvolved side despite a 28-dB hearing level (HL) worse (compared to the uninvolved side) pure-tone hearing threshold average for standard audiometric frequencies between 1 and 6 kHz at the involved side. In 3 of these patients, 2 with an inferior vestibular nerve origin of the acoustic neuroma and one in whom the nerve of origin could not be unequivocally defined, the tumor was extending extrameatally. One patient had a purely intrameatal acoustic neur…
Transient evoked otoacoustic emissions in vestibular neuritis.
2007
Objectives: Partial or total degeneration of the vestibulocochlear anastomosis at its takeoff from the saccular ganglion and regenerating efferent neural buds under the cochlear outer hair cells (OHCs) have been found in the temporal bones of human patients with a history of vestibular neuritis (VN). We sought to test whether VN has any functional impact on the ipsilateral OHCs by means of transient evoked otoacoustic emission (TEOAE) testing. Methods: We retrospectively analyzed prospectively collected TEOAE data of 28 patients (19 female, 9 male; age range, 21 to 60 years; median age, 42.5 years). The pure tone air conduction hearing thresholds at each standard audiometric frequency (0.12…
Evoked otoacoustic emissions and pure tone threshold audiometry in patients receiving cisplatinum therapy.
1993
Eight children and young adults with cancer were evaluated serially using pure tone audiometry as well as registration of click-evoked otoacoustic emissions (EOAE) 1 day prior to therapy as well as after various numbers of doses of cisplatinum. A reduction of EOAE-amplitudes following cisplatinum therapy was observed in all patients. This reduction tended to recover after the end of cisplatinum administration. Since EOAE are believed to result from cochlear bio-mechanical processes, the reduced emissions are interpreted as signs of cochlear dysfunction. We conclude, that EOAE testing may be a simple, non-invasive method that may detect early, transient functional impairment of hearing due t…
DPOAE‐Grams in Patients with Acute Tonal Tinnitus
2005
To investigate cochlear outer hair cell function in patients with acute tonal tinnitus and normal or near-normal hearing threshold.Prospective controlled study in an academic tertiary health center. Distortion products of otoacoustic emissions (DPOAE)-grams of 32 ears with acute tonal tinnitus and normal hearing or minimal hearing loss were compared with those of 17 healthy nontinnitus ears.Tinnitus ears exhibited relatively increased amplitudes of DPOAE at high frequencies (4-6.3 kHz) when compared with the group of healthy ears and relatively decreased DPOAE amplitudes at middle frequencies (1650-2400 Hz). Statistically significant ( P0.01) increased mean values of DPOAE amplitudes were o…
Clinical observations and risk factors for tinnitus in a Sicilian cohort.
2014
The aims of this study were to determine the distribution of risk factors associated with tinnitus analysing their role in the development of tinnitus and the effects of their interaction; to evidence the importance of a suitable and adequate clinical and audiologic assessment to avoid those modifiable risk factors responsible for cochlear dysfunction and tinnitus onset. 46 subjects with tinnitus and 74 controls were studied according to: age, sex, Body Mass Index (BMI), neck circumference, tobacco smoking, feeling fatigue or headache, self reporting snoring, hypertension, diabetes, coronary heart disease, and/or hyperlipidemia, and laboratory finding as lipid profile and levels of reactive…
Revealing deterministic structures in click-evoked otoacoustic emissions.
2000
Click-evoked otoacoustic emissions (CEOAEs) were studied by means of recurrence quantification analysis (RQA) and were found to be endowed with a relevant amount of deterministic structuring. Such a structure showed highly significant correlation with the clinical evaluation of the signal over a data set including 56 signals. Moreover, 1) one of the RQA variables, Trend, was very sensitive to phase transitions in the dynamical regime of CEOAEs, and 2) appropriate use of principal component analysis proved able to isolate the individual character of the studied signals. These results are of general interest for the study of auditory signal transduction and generation mechanisms.