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. Author manuscript; available in PMC: 2018 Dec 21.
Published in final edited form as: N Engl J Med. 2018 Jun 21;378(25):2376–2385. doi: 10.1056/NEJMoa1801109

Figure 1. Hearing Level among 101 Children Who Could Be Evaluated.

Figure 1.

A Brock grade of 0 indicates hearing at less than 40 dB at all frequencies and does not necessarily equate to completely normal hearing. Grades 1, 2, 3, and 4 indicate hearing levels at 40 dB or higher at 8 kHz, 4 kHz, 2 kHz, and 1 kHz and above, respectively.10 The grade was determined according to the hearing level in the child’s better ear. The numbers of children with each Brock grade are provided in Table S2 in the Supplementary Appendix.