FIG. 5.

Masking effectiveness of anodic and cathodic phases. A Example of ECAP recordings obtained with subject S1 for an anodic-first (thick line) and a cathodic-first (thin line) biphasic probe in the biphasic masking condition. The response latency is shorter for the anodic-first probe. B Latency of the cathodic-first probe response vs. latency of the anodic-first probe response. For each subject, the two probes were presented at an identical level (comfortably loud) and also at the same level as the biphasic masker. C, D, and E Example of ECAPs evoked by a symmetric biphasic probe with no phase separation in the three masker conditions: anodic masking (C), cathodic masking (D), and biphasic masking (E) for subject S1. Each trace corresponds to the average of the anodic-first and cathodic-first biphasic probe responses. In the cathodic masking condition, the neural response was sometimes not clearly measurable. In D, for example, there is no excursion of the trace in the negative portion of the graph. Nevertheless, the recording still shows a voltage increase in the same region where the probe neural response occurs. The amplitude of the probe response was, in this case, assumed to be the magnitude of this increase. F Summary of ECAP amplitudes obtained in the anodic-masking (black bars), cathodic-masking (white bars), and biphasic-masking (gray bars) conditions.