A hybrid trial to trial wavelet coherence and novelty detection scheme for a fast and clear notification of habituation: An objective uncomfortable loudness level measure

Abstract

Objective: To determine an uncomfortable loudness (UCL) level is not an easy task, especially in children. A need to objectively measure this level is crucial as the age of hearing devices candidates is getting younger. Previous studies have shown that the feasibility of habituation correlates in late auditory evoked potentials for a measurement technique of UCL identification is promising. Nevertheless, a scheme that could provide a fast and clear notification of an UCL level is reached is desirable. The present study has introduced a hybrid trial to trial wavelet coherence and novelty detection scheme to extract and to notify objectively the habituation correlates in late auditory evoked potentials. Methods: Data were obtained from 10 normal hearing subjects. The auditory stimuli were pure tones of 1 kHz with a duration of 40 ms and a constant interstimulus interval (ISI) of 1 s and presented at 50 desibel (dB) sound pressure level (SPL) and 100 dB SPL consecutively. Subject were in relaxing condition and awake over the experiment. Results: The proposed scheme is able to highlight the presence of habituation and the number of stimuli could be reduced up to 60% percent for meaningful results. Conclusions: Therefore, this paper has shown that the proposed approach provides an encouraging foundation for a fast and reliable scheme in developing an objective loudness scaling measurement, in particular in determining UCL level. © 2011 Springer-Verlag.