Figure 1

A schematic illustration of the participant selection process that was used in the present study. Out of a total of 1,025,340 participants, 5,135 severely hearing-impaired and 1,390 profoundly hearing-impaired participants were selected. The hearing-impaired participants were matched 1:4 with a control group that did not have a diagnosed hearing impairment. Finally, 4,432 severely hearing-impaired and 17,728 control participants and 958 profoundly hearing-impaired and 3,832 control participants were included.