Cortical reorganization following auditory spatial training in listeners with sensorineural hearing impairment: A high-density electroencephalography study

Abstract

The present study is intervention-based research aimed at remediation of spatial deficits in listeners with sensorineural hearing impairment (SNHI), through the use of virtual acoustic technology. A mixed group design comprising both within (pre-test, post-test control group design) and across the groups (standard group) comparisons were performed. The study included 37 participants, who were divided into three groups. Groups I and II consisted of SNHI listeners, while group III comprised normal hearing (NH) listeners. The study was conducted in three phases. At the pre-training phase, electroencephalographic (EEG) recordings were acquired from all the three groups using spatial deviants presented in P300 paradigm. Following this, group I listeners underwent virtual acoustic space training (VAST), and post-training EEG recordings were obtained. EEG recordings were also acquired from group II listeners in second evaluation without subjecting them to any formal spatial training. Results of unpaired t-tests, grand average waveforms and scalp topographies of offline processed waveforms revealed significant differences between SNHI and NH listeners. Furthermore, spatio-temporal analyses showed the emergence of new scalp maps in post-training phase in trained listeners and no topographic changes in untrained SNHI group, suggestive of benefit derived from VAST right at the fundamental level (cortical) of spatial processing.