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Eighteen post-lingually deafened, adult CI users (10 females, M = 59.89, SD = 13.06 years) were<br />
recruited from the South of England Cochlear Implant Centre in Southampton, UK. All CI users were<br />
right-handed and had no history of neurological or psychiatric disorders. All but one CI user were<br />
unilaterally implanted and all CI users had at least 6 months experience with the implant (CI<br />
experience: M = 40.22, SD = 36.60 months). Details about the clinical profile of the CI users are<br />
shown in Table 1. Procedures were approved by the local ethics committee and con<strong>for</strong>med to the<br />
declaration of Helsinki.<br />
2.2.2. Stimuli and Task<br />
CI users were stimulated with 80 environmental sounds with 400 ms duration and a sampling rate of<br />
22 kHz via two loudspeakers (Quad L12) positioned at an azimuth of 45°/135° in front of the<br />
participant. Sounds were presented at a com<strong>for</strong>table level adjusted individually <strong>for</strong> each participant<br />
using a five level loudness com<strong>for</strong>t rating scale varying from 60 to 80 dB SPL in steps of 5 dB SPL.<br />
CI users were using their implant on their standard everyday settings. The environmental sounds were<br />
used as primes in a semantic priming paradigm (Viola, et al., 2011).<br />
2.2.3. Electrophysiology recordings<br />
CI users were seated in an electrically shielded, sound attenuated and dimly lit booth (Industrial<br />
Acoustics, Winchester, UK) and EEG data were recorded from 68 channels using a high-input<br />
impedance amplifier system (Compumedics Neuroscan, Charlotte, NC, USA) and a customized,<br />
infracerebral electrode cap with an equidistant electrodes lay-out (Easycap, Herrsching, Germany).<br />
Data were recorded with a sampling rate of 1000 Hz using the nose-tip as reference, and were<br />
analogue filtered between 0.1 and 200 Hz. Electrode impedances were maintained below 20 kΩ prior<br />
to data acquisition.<br />
2.2.4. Data processing<br />
EEG data were processed using custom scripts and EEGLAB (Delorme and Makeig, 2004) running in<br />
the MATLAB (Mathworks, Natick, MA) environment. Data were filtered offline from 1 to 40 Hz<br />
using sinc FIR filters windowed with a Hann window (courtesy of A. Widmann: www.uni-<br />
leipzig.de/~biocog/content/widmann/eeglab-plugins/). Data were then down-sampled to 500 Hz and<br />
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