About COBALT

COBALT (Click Ordering Binaural Adaptive Lateralization Test) measures your temporal order judgment (TOJ) threshold — the smallest time gap between two sounds at which you can reliably tell which ear heard it first.

How it works

Two sounds are played in rapid succession, one to each ear, with a gap of $\Delta t$ milliseconds. After each trial, you indicate which ear heard the sound first. The gap adapts using a 2-down 1-up staircase, converging on the 70.7% correct threshold:

$$\hat{\theta} = \frac{1}{4}\sum_{i=3}^{6} r_i$$

where $r_i$ is the gap (in ms) at the $i$-th reversal.

References

• Wetherill, G. B., & Levitt, H. (1965). Sequential estimation of points on a psychometric function. British Journal of Mathematical and Statistical Psychology, 18(1), 1–10.