1,721,020 research outputs found
The International Association of Physicians in Audiology: from the Bulletin to HBC, a history 40 years long
No full textIdentification of heaving loss using TEOAE descriptors: Theoretical foundations and preliminary results
No full textAudioscan automatic audiometry: theoretical basis and normative data
No full textAudioscan automatic audiometry is a high resolution method to explore hearing thresholds in the 125 Hz-16 KHz range offering a resolution of 64 points per octave. This procedure makes it possible to study hearing threshold levels at intermediate frequencies which are not measured by conventional audiometry. As suggested in the literature, it is possible to identify hearing threshold notches, considered indicators of mild or subclinical cochlear pathology. In clinical practice, the use of a new audiometric technique requires affirmation of reliability, sensitivity and replicability in time. It also requires defining standard criteria for use in various otologic pathologies. The present study examined 50 normal hearing subjects with conventional audiometry and Audioscan (Essilor model) measurements. A standard acquisition protocol was followed where three Audioscan measurements were conducted per subject. Subjects with a history of acute otologic pathology and familiarity for genetic deafness were ruled out of the study. Multiple, pairwise correlation analyses of the audiometric and Audioscan responses indicate that: (1) there are no significant differences between threshold levels measured by Audioscan and conventional audiometry; (2) there are no significant variations in the hearing levels measured by three Audioscan retests. Three mean indicators of the threshold level have been defined, expressing Audioscan normality in three different frequency ranges. The data suggest that there are some difficulties in the subjectivity of the Audioscan method and some technical problems regarding the lower octave frequencies and these need to be addressed. The results obtained in this study confirmed reliability of the Audioscan in the mid and high frequencies. The definition of the standard mi criteria makes it easier to interpret the Audioscan measurements from cases presenting various otologic pathologies. Therefore, the plasticity and high detection sensitivity of hearing loss make the automatic Audioscan audiometry a useful clinical tool for diagnostic and/or preventive purposes
Neonatal hearing screening in Albania: results from an ongoing universal screening program.
No full textThe paper describes the outcomes of an ongoing universal hearing screening program in Tirana, Albania. The main objectives of the project were the evaluation of the feasibility of a neonatal hearing screening program in Albania, and an evaluation of the prevalence of risk factors in the NICU environment. One thousand five hundred and sixty-one (1561) infants from both the WB and NICU were screened with transient evoked otoacoustic emissions (TEOAE). A detailed history of risk factors was collected in each case, thus it was possible to evaluate the main factors influencing the output of the screening program. It was concluded that the program had the capacity to identify infants with congenital hearing loss provided that an informative component is well-structured and delivered. Also, although the prevalence of risk factors appeared high, the reduction of 'case leakage' would allow the precise estimation of the incidence of hearing loss in the Albanian population
Detection of hearing losses (HL) via transient-evoked otoacoustic emissions: towards an automatic classification
Full text linkTransiently evoked otoacoustic emissions (TEOAEs) are routinely used in the hearing assessment of the auditory periphery. The major contribution of TEOAEs is the early detection of hearing losses in neonates, children, and adults. The evaluation of TEOAE responses by specific signal decomposition techniques offers numerous advantages for current and future research. One methodology, based on recurrence quantification analysis (RQA), can identify adult subjects presenting sensorineural hearing impairments. In two previous papers, the RQA-based approach was successfully applied in identifying and classifying cases presenting noise and age related hearing losses. The current work investigates further two aspects of the previously proposed RQA-based analysis for hearing loss detection: (i) the reliability of a Training set built from different numbers of ears with normal hearing, and (ii) the threshold set of values of the key hearing loss detecting parameter RAD2D.Results:The Training set built from 158 healthy ears was found to be quite reliable and a similar but slightly minor performance was observed for the training set of 118 normal subjects, used in the past; the proposed ROC-curve method, optimizing the values of RAD2D, shows improved sensibility and specificity in one class discrimination.Conclusions.A complete and simplified procedure, based on the combined use of the traditional TEOAE reproducibility value and on values from the RQA-based RAD2D parameter, is proposed as an improved automatic classifier, in terms of sensitivity and specificity, for different types of hearing losses
Optimizing otoacoustic emission protocols for a UNHS program.
No full textOBJECTIVE: To identify the optimal test protocol to screen for hearing problems in newborns, an evaluation of three distortion product otoacoustic emission (DPOAE) protocols was conducted in neonates, from a well-baby nursery (WBN) and from a neonatal intensive care unit (NICU) and compared to the performance in newborns of a more standard protocol based on transient-evoked OAEs (TEOAEs). METHODS: The DPOAE protocols used asymmetrical stimulus intensities (L(1) > L(2)) with a frequency ratio of 1.22, in the following format: (P1), L(1) = 60, L(2) = 50 dB SPL; (P2), L(1) = 65, L(2) = 55 dB SPL, and (P3), L(1) = 75, L(2) = 65 dB SPL. Linear TEOAE responses, evoked by click stimuli of 75 dB peSPL, were used as controls of normal cochlear function. Five frequencies at 1.5, 2.0, 3.0, 4.0 and 5.0 kHz were tested with a common commercially available macro-based software subroutine (Otodynamics Corp, ILO-92). The project evaluated the responses from 1200 WBN infants (average age 48 h) and 350 low-birth-weight NICU infants, all randomly selected. RESULTS: Statistical analyses comparing the signal-to-noise ratios (S/N), at the predefined f(2) frequencies, indicated that the P1 and P2 DPOAE protocols generated similar responses. Significant S/N differences were observed in the P3 to P2 dataset comparisons. DPOAE scoring criteria were estimated from the P3 dataset using a one-sided, distribution-free confidence intervals. The scoring criteria for a 'pass' were estimated as a minimum S/N of 6.0, 7.0 and 6.0 dB at 2.0, 3.0 and 4.0 kHz, respectively. In terms of feasibility, the P3 protocol generated responses in 98% of the WBN and 94.8% of the NICU infants. CONCLUSIONS: All three DPOAE protocols demonstrated shorter time-recording requirements than the standard TEOAE test. The false-positive and false-negative rates for the NICU infants were estimated as 0.0028 and 0.003%, respectivel
Evaluation of anesthesia effects in a rat animal model using otoacoustic emission protocols.
No full textAnesthesia effects on otoacoustic emission (OAE) recordings were evaluated in a group of 72 Sprague-Dawley rats (mean weight 225+/-20 gr). Two anesthesia dosages (high and normal) and two anesthetic protocols (ketamine-xylazine, ketamine-xylazine-atropine) were tested. Transient evoked OAE (TEOAE) and distortion product OAE (DPOAE) responses were recorded in 10 min intervals, for a total period of 60 min. Analyses of the data with repeated measure models indicated the following: (1) The animals receiving a high dose of anesthesia (cumulative dose 66.6 mg of ketamine and 13.2 mg of xylazine/kg of body weight) presented significant alterations of the TEOAE response level and the signal to noise ratio at 3.0 kHz; (2) the animals receiving a normal dose of ketamine-xylazine anesthesia (cumulative dose 50 mg of ketamine and 10 mg of xylazine/kg of body weight) presented TEOAE and DPOAE responses invariant in terms of time; (3) significant differences were observed in the DPOAE responses from animals anesthetized with ketamine-xylazine and ketamine-xylazine-atropine. The data support the hypothesis that the ketamine anesthesia OAE suppressing mechanism is related to middle-ear mechanics
Time-frequency analyses of TEOAE recordings from normals and SNHL patients.
No full textThis study evaluated the characteristics of transient evoked otoacoustic emission (TEOAE) time-frequency (TF) representations from normal and hearing-impaired ears. Linear and non-linear TEOAE recordings from normally-hearing subjects (40) and non-linear recordings from patients with sensorineural hearing loss (SNHL) (40) were analysed using the short-time-Fourier-transform spectrogram, the Gabor spectrogram, and the adaptive spectrogram. The TF representations of the TEOAE recordings indicated a considerable dispersion of energy across frequencies and TEOAE time segments >4.0 ms. The linear and non-linear recordings from the normal subjects showed common frequency peaks. The TF representations from the patients with SNHL indicated that the significantly reduced energy in the mid-to-high TEOAE frequencies did not correlate closely with the threshold elevation. As in the recordings from the normal subjects, a high percentage of the TEOAE cumulative energy was found within a short TEOAE segment (4-14 ms)
Distortion product otoacoustic emission (DPOAEs) and newborn hearing screening: a feasibility and performance study
No full textIn view of the great psychological effect deafness has on one's social life, the scientific community has long sought the best way to define the hearing function. The development of new technologies in this field has set "early intervention" as the primary target for screening. For this reason, within the contest of a program of audiological newborn hearing screening, the Authors have used data from a selected group of 1250 newborns to (a) compare the clinical feasibility and performance of three different DPOAE protocols and (b) establish the scoring criteria defining "pass" or "fail" responses. All subjects participating in this study were randomly selected and their normal hearing was verified by linear TEOAE recordings. The test was carried out, using an Otodynamics ILO92 Analyser version 5.60, on the second day of life or later (in case of extended recovery), during natural sleep and after feeding. The DPOAE recordings were elicited using asymmetric stimuli with L1 > L2 and a frequency-ratio of 1.22 following three different SPL protocols: 60-50 dB (PR1), 65-55 dB (PR2) and 75-65 dB (PR3). Five frequencies of the cubic distortion product (referring to f2) were tested with an ILO macro at 1.5 KHz, 2.0 KHz, 3.0 KHz, 4.0 KHz and 5.0 KHz. The statistical evaluation of differences in the signal-to-noise ratio (S/N) between the PR1 and PR2 protocols showed no significant differences. On the other hand significant differences were found between the PR3 and the PR2 S/N ratios, the former providing the best performance (higher values). The scoring criteria were defined by minimum free distribution tolerance intervals of the S/N ratios at the five tested frequencies. In conclusion this study confirms the feasibility of DPOAE recordings in a un iversal newborn hearing screening program and shows the appropriate pass-fail parameters to be used for this purpose. It should be noted that this approach enables acquisition of frequency-specific information which might further improve audiological diagnosis
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