Figure 3. Effect of level sampling on algorithmic fitting.
A: An ABR level series in response to 12.1 kHz tone-pips, with visual thresholds for Observers 1 & 2 indicated by thicker traces. B-D: The effects of undersampling are illustrated by removing subsets of averaged waveforms, rerunning the cross-covariance analysis and fitting the resultant points. E-H: For each set of original or undersampled waveforms, the correlation-coefficient vs. level functions are fit using either sigmoidal (blue) or power (pink) functions. The green line shows the criterion level of 0.35. The algorithmic threshold and its corresponding 95% prediction interval is shown in the panel corresponding to the fitting scheme chosen by the algorithm.
