gms | German Medical Science

We propose for the first time Gabor frame operators as efficient feature extraction technique for ABR single sweeps that can be processed using a novelty detection paradigm. We use this decomposition technique to derive the Gabor frame phase stability (GFPS) of ABRs sweeps.

Chirp and click evoked ABRs were obtained from 20 volunteers (threshold<15dB(HL);24.45 ± 3.80 years;13/7female/male) with no history of hearing problems. In each experiment 2 types of electrodes passive (PE) and active (AE) were used (Impedances remained< 5KΩ).

First AE were attached and ABRs were obtained using clicks at intensity levels of 40, 30, 20 dB(SPL) and the spontaneous activity (no stimulation). Later the chirps were presented for the same intensity levels. Then, the electrodes were changed for PE and the same stimulation procedure was applied. Each condition had 2000 sweeps free from amplitude artefacts (15µVolts).

We show that the GFPS of chirp evoked ABRs provide a stable discrimination of the spontaneous activity from stimulations above the hearing threshold with a minimum number of sweeps, especially for the chirp stimulations. This is the first study directed to an ultrafast single sweep analysis of chirp evoked ABRs.

It is concluded that the GFPS represents a robust feature of ABRs which allows for an ultrafast discrimination of the spontaneous activity from stimulation intensities above the hearing threshold, especially for chirp stimulations, and might be used in expert based diagnostic procedures directly or for the ultra-fast detection of the hearing threshold by cojoint systems with a computational decision making stage according to the novelty detection paradigm. We conclude that our study reinforces the use of chirp stimulations for the fast hearing threshold detection.