This study investigated whether a short intensive psychophysical auditory training
program is associated with speech perception benefits and changes in cortical auditory
evoked potentials (CAEPs) in adult cochlear implant (CI) users. Ten adult implant
recipients trained approximately 7 hours on psychophysical tasks (Gap-in-Noise Detection,
Frequency Discrimination, Spectral Rippled Noise [SRN], Iterated Rippled Noise, Temporal
Modulation). Speech performance was assessed before and after training using Lexical
Neighborhood Test (LNT) words in quiet and in eight-speaker babble. CAEPs evoked by
a natural speech stimulus /baba/ with varying syllable stress were assessed pre- and
post-training, in quiet and in noise. SRN psychophysical thresholds showed a significant
improvement (78% on average) over the training period, but performance on other psychophysical
tasks did not change. LNT scores in noise improved significantly post-training by
11% on average compared with three pretraining baseline measures. N1P2 amplitude changed
post-training for /baba/ in quiet (p = 0.005, visit 3 pretraining versus visit 4 post-training). CAEP changes did not
correlate with behavioral measures. CI recipients' clinical records indicated a plateau
in speech perception performance prior to participation in the study. A short period
of intensive psychophysical training produced small but significant gains in speech
perception in noise and spectral discrimination ability. There remain questions about
the most appropriate type of training and the duration or dosage of training that
provides the most robust outcomes for adults with CIs.
Keywords
Cochlear implant - cortical auditory evoked potential - auditory rehabilitation -
auditory training - auditory plasticity - speech in noise
