Poul Aabo Osterhammel

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The aim of the study was to analyse whether the presence of spontaneous otoacoustic emissions (SOAEs) in a group of normal-hearing adults is related to larger transient evoked otoacoustic emission (TEOAE) amplitudes when compared to a similar adult population without SOAEs. Twenty-four normal-hearing subjects participated in the investigation. They were(More)
Parametric variations in the ratio of primary-tone frequencies were explored to optimize the amplitude of the 2f1-f2 distortion product otoacoustic emission for clinical purposes. Ten ears from 5 normally hearing human subjects were examined with primary tones geometrically centred around the standard audiometric frequencies of 0.5, 1, 1.5, 2, 3, 4, 6 and 8(More)
The effect of systematic variations in the relative levels (L1, L2) of two primary tones (f1, f2) on the amplitude of the distortion product otoacoustic emission (DPOAE) at 2f1-f2 and f1 < f2 was investigated in 14 ears from 7 normally hearing human subjects. The primary tones (f2:f1 = 1.23) were geometrically centred at the standard clinical frequencies of(More)
Auditory SN-10 responses and summed middle latency responses (40/sec MLR) were obtained from 36 full-term newborns. Wave V latencies from 20-70 dB nHL were in agreement with previous studies. Although the amplitudes of the SN-10 and the 40/sec MLR paradigms were not significantly different, we were able to detect the lowest thresholds with an SN-10 response(More)
286 normal subject representing both sexes and seven age groups from 10 to greater than or equal to 70 years were tested with both conventional pure tone audiometry and high frequency audiometry (4--20 kHz) using a previously described free field system. The subjects were selected according to very strict criteria. Results from conventional audiometry are(More)
The ABR and the MLR were measured without interruption in 4 subjects during a whole night of natural sleep and compared with the awake responses. The conventional EEG activity was monitored during the whole procedure, which permitted a precise rating of the sleep stage during each recording period. Only minor changes were found in the latencies for the ABR(More)
The general routine for recording the auditory brainstem responses (ABR) includes the use of earlobe electrodes as reference. Electrically linked electrodes on each side of the neck are almost indifferent with regard to the ABR, and such electrodes were used as reference in an analysis of the response patterns at the vertex and both earlobes. These(More)
This study addressed the hypotheses that the growth of the level of distortion product otoacoustic emissions (LDP) with primary-tone level reflects the behavior of a third-order nonlinear polynomial system, and that two sources exist for these distortion products. The results indicated that the 2f1-f2 otoacoustic emission in humans can be measured over a(More)
The most interesting electrode positions for recording the FFR are the Vertex and the mastoid. The response is greatest at the Vertex. At the mastoid it comes earlier and probably in a different phase. As a combined result of these relations the responses are in opposite phase with a 500 Hz stimulus, and at 400 Hz they are in-phase. The Vertex-derived(More)