Figure 1.
The recording conditions to obtain an ECAP in single pulse recording and in pulse train recording (I) and how the ECAP to an individual pulse in the train was derived (II).
See the text in Methods section for detailed information on how to derive the ECAP to an individual pulse in the train.
Figure 2.
Normalized ECAP amplitudes as the function of pulse number in the 50-ms pulse train.
Each trace in dark gray represents data from one subject and the trace in black represents the mean data. Normalized ECAP amplitude was calculated by dividing the ECAP amplitude to pulse 2 to pulse 51 in the train by the ECAP amplitude in the single pulse recording. An alternating pattern is observed in every subject.
Figure 3.
Examples of the EEG responses contaminated by stimulus artifacts (top plots) and the LAEPs after artifact removal (bottom plots) at the vertex electrode recorded from two CI subjects.
It can be seen that the CI subject on the left shows a more prominent adaptive pattern than the CI subject on the right (the response to the 1st stimulus is larger than the responses to the later stimuli in the train). Note that the y-axis of the top plots before ICA procedure has a different scale compared to other plots due to the large artifacts.
Figure 4.
The averaged LAEP waveforms evoked by individual stimulus in the train for the NH group (left) and the CI group (right).
Figure 5.
The normalized amplitude of the LAEP as a function of stimulus order for individual CI subjects.
Each trace in dark gray represents data from one subject and the trace in black represents the mean data. Normalized LAEP amplitude was calculated by dividing the LAEP amplitude to an individual stimulus in the train by the LAEP amplitude evoked by the first stimulus in the train.
Figure 6.
The correlation between adaptation index and the CGDT in CI users.
Figure 7.
The correlation between adaptation index and speech perception scores (the average scores of CNC and AzBio) in CI users.
Figure 8.
The correlation between adaptation index and demographic factors including the duration of deafness, the age at implantation, and the length of CI use.
Among all the scatter plots, the correlation between AILAEP and the age of implantation is statistically significant, if one outlier that shows amplitude enhancement rather than adaptation is not included in the analysis.