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E Stürzebecher

Publications and source records attributed to E Stürzebecher.

At least 19 recordsLinked to original sources
PubMed2001

Objective detection of transiently evoked otoacoustic emissions.

Newborn hearing screening with transiently evoked otoacoustic emissions (TEOAE) is a well-established method. A screening device must be equipped with a test procedure for objective TEOAE detection. The statistical tests implemented in the commercially available screening devices are the correlation, an estimation of the signal-to-noise ratio and a binominal test. The aim of the present study is to compare the TEOAE detection performance of these tests with that of several other tests in the time and frequency domains (variance ratio F(SP) and its modification F(SP)*, Friedman test, modified q-sample uniform scores test). The comparison was based on a data sample of 420 TEOAE. The frequency range examined was 1.5-4.0 kHz. As a new feature, two frequency sub-ranges (1.5-2.5 kHz, 2.5-4.0 kHz) were tested separately. The modified variance ratio F(SP)* was the most powerful test, whereas the tests implemented in the known screening devices showed the lowest detection performance.

Acoustic Stimulation↗
PubMed2000

Objective detection of auditory brainstem potentials: comparison of statistical tests in the time and frequency domains.

Newborn hearing screening with auditory brainstem potentials (ABR) requires objective ABR detection by a statistical test procedure with high performance. Statistical testing can be performed in the time or frequency domain. The aim of the present study was to compare the performance of three tests in the time domain (Friedman test, variance ratio F(SP), Cochran's Q-test) with that of a test in the frequency domain (modified q-sample uniform scores test) that, in a former investigation, was shown to be the best test in the frequency domain. To compare the performance of the four tests, the test power was calculated and receiver operating characteristics (ROCs) were constructed from the probability density functions estimated using Monte Carlo simulations. In addition, a comparison on the basis of real near-threshold ABR data was carried out. The modified q-sample uniform scores test appeared to be the most powerful one. Some aspects of practical application are discussed.

Adult↗
PubMed1997

Objective detection of auditory evoked potentials. Comparison of several statistical tests in the frequency domain on the basis of near-threshold ABR data.

A fully objective electric response audiometry (ERA) requires an objective response detection by an appropriate statistical test. The Rayleigh test, Watson's U2 test, Kuiper's test and Hodges-Ajne's test check the phase angle distribution of a Fourier harmonics. The modified Rayleigh test uses, in addition to the phase angles, the amplitude information in the form of the ranks of the spectral amplitudes, whereas magnitude-squared coherence (MSC) uses the spectral amplitudes themselves. The signal detection performance of these six tests was judged on the basis of a sample of near-threshold click-evoked ABR. MSC was found to be the best suited test out of the six tests investigated, but the performance differences to the modified Rayleigh test (and even to the unmodified Rayleigh test), and to Watson's test as well were only slight. Hodges-Ajne's test and Kuiper's test have the lowest sensitivity and the mean time required for response detection is longest for Hodges-Ajne's test.

Adult↗
PubMed1996

Objective detection of auditory evoked potentials. Comparison of several statistical tests in the frequency domain by means of Monte Carlo simulations.

Fully objective assessment of the hearing threshold by auditory evoked potentials requires an objective detection of these responses by means of suitable statistical tests. The Rayleigh test, Watson's U2 test, Kuiper's test and Hodges-Ajne's test check the phase angle distribution of a Fourier harmonics in a sample of stimulus-related EEG epochs. The modified Rayleigh test includes, in addition to the phase angles, the amplitude information in the form of ranks of the spectral amplitudes. To compare the signal detection performance of these tests, estimates of the probability density functions were calculated by means of extensive Monte Carlo simulations. From the probability density functions, the sensitivity of the tests was calculated and receiver operating characteristics (ROC) were constructed. The modified Rayleigh test appeared to be the most powerful test, followed by the Rayleigh test and Watson's U2 test. The application of Kuiper's test and Hodges-Ajne's test as well is not to be recommended for AEP detection.

Auditory Threshold↗
PubMed1988

Influence of age, sex, and hearing loss on auditory brain stem response (ABR) latencies.

In a previous paper, the hypothesis was established that the shorter auditory brain stem response (ABR) latencies in females, in comparison with males, can be explained solely by the age dependence of the latencies, which is more pronounced in males than in females. According to this concept, ABR latencies in male and female babies are identical but diverge increasingly with increasing age. A multiple regression analysis on considerably enlarged male and female groups has now confirmed the hypothesis as to the differing age dependence in males and females. But the results also show that the male/female ABR latency differences cannot be explained solely by these differences in age dependence. An additional factor has to be taken into account, for which the male/female difference in auditory pathway length is a plausible explanation.

Adult↗
PubMed1987

Effects of age and sex on auditory brain stem response. A new aspect.

The age and sex dependence of the latencies and interpeak intervals (IPI) of the auditory brain stem response (ABR) was investigated in 86 males and 69 females. The latencies of the waves I, III and V as well as the IPI I-V and III-V are significantly shorter in females than in males. A correlative linear dependence on age could be shown for the latencies of waves I, III and V in males and for the wave V latency in females. The slopes of the regression lines calculated for the dependence of ABR latencies I, III and V on age tend to be steeper in males than in females. The slope increases from wave I to wave V. The male and female regression lines intersect the latency axis at about the same point (at the same latency value at age A = O). On the basis of these results, the hypothesis is established, that age and sex dependence is not caused by different mechanisms. The ABR latency differences between males and females are in the main the result of the ABR age dependence being less pronounced in females than in males.

Aging↗
PubMed1985

Detectability of the acoustically evoked composite response (40 HZ potential) near threshold.

In 56 persons with normal hearing and 10 patients with sensorineural hearing loss, acoustically evoked potentials were recorded at stimulus repetition rates of 10/s, 20/s, 30/s and 40/s. With a sufficiently low lower amplifier cut-off frequency, one obtains at the repetition rate of 40/s a composite response described by Galambos et al. (1981) as 40 Hz potential, which consists of the ABR evoked by the given stimulus and superposed MLR-waves evoked by the preceding stimuli. In both groups the amplitude mean value of the potentials recorded at the stimulus rate 40/s was significantly higher than at lower rates. The detectability of the near-threshold response for the subjects with normal hearing was distinctly higher than the responses recorded at lower rates.

Acoustic Stimulation↗
PubMed1985

Interpeak intervals of auditory brainstem response, interaural differences in normal-hearing subjects and patients with sensorineural hearing loss.

ABR recordings were made on 31 normal-hearing subjects and 253 patients with sensorineural hearing loss (86 patients with unilateral hearing loss, 61 patients with asymmetrical hearing loss, 34 patients with symmetrical hearing loss, 55 patients with noise-induced hearing loss and 17 patients in the late chronic stage of Menière's disease). In the patient group with unilateral hearing loss, the mean interpeak interval (IPI) I-V was significantly shorter than in normal-hearing subjects. The interaural IPI differences provide a sharp criterion for early detection of acoustic neuroma. The calculation of the 95%-limits (means + 1.96 SD) showed that in patients with normal hearing or with unilateral or symmetrical hearing loss an interaural difference in the IPII-V greater than 0.2 ms has to be considered as an indication of a neuroma or any other brainstem abnormality. In patients with asymmetrical or with noise-induced hearing loss, the limit is 0.3 ms. In contrast to the frequently recommended interaural wave V latency difference criterion, the interaural IPI difference criterion requires no correction for audiogram differences.

Brain Stem↗
PubMed1978

[Multivariate variability investigations of acoustically evoked slow potentials (AEP) (author's transl)].

By means of the multivariate variance analysis the ratio of intra- and interindividual variability of the AEP--time function was investigated. 90 AEP from 9 normal hearing persons (10 AEP from every person, averaging sessions spread over 10 weeks) were analyzed. The 10 AEP of every person were treated as a random sample. A multivariate pair comparison (single comparison between samples) on the basis of 12 variables (time points) showed only for 1 out of 36 sample pairs no significant differences between the sample averages. By applying the discriminant analysis false classifications resulted only for 7 out of the 90 AEP (approximately 8%). These facts mean, that even throughout the time of 10 weeks the intraindividual differences of the AEP--time behavior are significantly smaller than the interindividual ones.

Acoustic Stimulation↗
PubMed1977

[The proof of age differences of slow acoustically evoked potentials of adults by a multivariate statistical analysis (author's transl)].

Many authors consider the nature of the slow acoustically evoked potentials to be partly a specific one. Therefore the AEP-time behavior probably contains more information about the functional state of the acoustical channel than it is got by the usual measurement of only 3 values (N1P2-amplitude, 2 latencies). A test of this hypothesis is possible with a multivariate mathematical procedure, which involves the whole AEP-time behavior. We are using the multivariate variance- and discriminant analysis. For the application of this statistical method random samples of patients with certain otologic diseases are needed. To avoid mistakes in grouping these samples some preliminary investigations had been necessary: This paper reports the results of multivariate investigations concerning age differences of the AEP in normal hearing adults. By means of the multivariate variance analysis the AEP of 3 age groups were examined (group 1: 15--34 years, group 2: 35--44 years, group 3: 45--60 years). At 1000 Hz as well as at 400 Hz significant differences between the group averages were found, which were not detectable by the usual N1P2-amplitude measurement. Furthermore with the discriminant analysis it is possible to perform a relatively reliable differentiation between the individual AEP of the age groups 1 and 3.

Acoustic Stimulation↗