Table 2.

Proposed ABR-derived adverse event schema. This application requires data collected using air-conducted tone burst stimuli from 0.5 to 4 kHz and assumes normal middle ear function.

Adverse Event Grade	ABR Findings (.5–4 kHz assessment)
1	Threshold shift >10 to ≤20 dB at 4 kHz in at least one ear
2	Threshold shift >20 dB at 4 kHz in at least one ear
3	Threshold shift >20 dB at 2 kHz in at least one ear
4	Absolute thresholds >80 dB eHL from 1–4 kHz in both ears (not previously present at baseline)

eHL: estimated hearing level