Auditory streaming and listening effort: An event related potential study

Until now, an objective method to estimate listening effort with a minimum level of cooperation of the patient in order to fit hearing aids is not existent. The benefit of such a method would be to reduce the listening effort in hearing impaired persons by an adequate adaption of the hearing aids. Recently, we have shown that the wavelet phase synchronization stability (WPSS) of auditory late responses could serve as a measure to estimate listening effort. In this paper, we extend our previous studies by using for the first time syllable stimulation paradigms with two levels of difficulty due to the combination of the syllables. Furthermore, by taking the model of auditory stream selection into account, the complexity of the paradigms was enhanced by the generation of a second competing auditory stream beside the syllable stream. This stream consisted of multitalker babble noise at two different signal to noise ratios in order to mimic noisy environments. The data was collected from a total of 21 normal hearing subjects, who had always to detect a target syllable. It is concluded, that the WPSS is a robust measure to perceive differences between the effort needed to solve a task in an easy and a difficult listening condition. However, a further research will be to test hearing impaired persons to prove, if this electrophysiological method could be applied to improve the hearing aid fitting procedures in clinical settings.