Table 3: Electrocochleography criteria [27]. The diagnostic level was chosen as the nearest whole figure to the level which provides a false-positive diagnosis rate of 5%. The likelihood of hydrops is a Gibson score of >7/10 [6]. Clicks: abnormal if SP/AP ratio ≥0.50.

Tone bursts Tone burst frequency Hearing level dBHL Abnormal if SP ≤ 0.5 kHz (75 dBHL) Under 25 −2 μV 20–35 −2 μV 40–55 −2 μV 60–75 −1 μV 1 kHz (90 dBHL) Under 25 −6 μV 20–35 −6 μV 40–55 −6 μV 60–75 −3 μV 2 kHz (100 dBHL) Under 25 −9 μV 20–35 −7 μV 40–55 −5 μV 60–75 −5 μV 4 kHz (75 dBHL) Under 25 −9 μV 20–35 −5 μV 40–55 −5 μV 60–75 −5 μV