| Adverse event | Grade 1 | Grade 2 | Grade 3 | Grade 4 | Grade 5 |
| Hearing impaired | Adults enrolled on a monitoring program (on a 1, 2, 3, 4, 6, and 8 kHz audiogram): Threshold shift of 15 to 25 dB averaged at two contiguous test frequencies in at least one ear Adults not enrolled on a monitoring program: Subjective change in hearing in the absence of documented hearing loss Pediatric (on a 1, 2, 3, 4, 6, and 8 kHz audiogram): Threshold shift >20 dB hearing loss (ie, 25 dB hearing loss or greater); sensorineural hearing loss above 4 kHz (ie, 6 or 8 kHz) in at least one ear | Adults enrolled on a monitoring program (on a 1, 2, 3, 4, 6, and 8 kHz audiogram): Threshold shift of >25 dB averaged at two contiguous test frequencies in at least one ear Adults not enrolled on a monitoring program: Hearing loss with hearing aid or intervention not indicated; limiting instrumental ADL Pediatric (on a 1, 2, 3, 4, 6, and 8 kHz audiogram): Threshold shift >20 dB at 2 to <4 kHz in at least one ear | Adults enrolled on a monitoring program (on a 1, 2, 3, 4, 6, and 8 kHz audiogram): Threshold shift of >25 dB averaged at three contiguous test frequencies in at least one ear; therapeutic intervention indicated Adults not enrolled on a monitoring program: Hearing loss with hearing aid or intervention indicated; limiting self-care ADL Pediatric (on a 1, 2, 3, 4, 6, and 8 kHz audiogram): Hearing loss sufficient to indicate therapeutic intervention, including hearing aids; threshold shift >20 dB at 2 to <4 kHz in at least one ear | Adults: Decrease in hearing to profound bilateral loss (absolute threshold >80 dB hearing loss at 2 kHz and above); nonservicable hearing Pediatric: Audiologic indication for cochlear implant; >40 dB hearing loss (ie, 45 dB hearing loss or more); sensorineural hearing loss at 2 kHz and above |
