Figure 1

Two hypothetical cases showing two different patterns of idiopathic sudden sensorineural hearing loss (ISSNHL) classified as having similar severity using current diagnostic criteria. In Case 1, hearing threshold levels on healthy side are almost in the normal range. In Case 2, hearing threshold levels on healthy side are in the range of mild to moderate hearing loss. x symbols and dashed lines indicate threshold values on the left (affected) side; open circles and solid lines indicate threshold values on the right (healthy) side.