Ototoxicity monitoring is a schedule of hearing tests before, during and after treatment with a drug that can damage the inner ear, such as cisplatin or an aminoglycoside antibiotic. Each test is compared with the person's own baseline, and grading scales decide whether a change counts and how severe it is.

Why it matters for tinnitus

Hearing damage from platinum chemotherapy typically appears as high-frequency loss, often with tinnitus, starting at the highest pitches and spreading toward speech frequencies as the dose accumulates, so testing above 8 kHz can catch it early. The American Speech-Language-Hearing Association (ASHA) says monitoring should find damage before the patient notices it, while a dose change or a less toxic drug is still possible; dose and blood levels alone cannot predict who will be harmed. Tinnitus severity cannot usually be read from an audiogram, so the scales grade it separately or leave it out.

What the evidence says

  • Guideline (ASHA, 1994). Baseline within the week before the first cisplatin or carboplatin dose, or within 72 hours of starting an aminoglycoside; retests before each platinum dose, or weekly on aminoglycosides; follow-up after treatment and at 3 and 6 months. A confirmed drop of 20 dB or more at one frequency, 10 dB or more at two adjacent frequencies, or lost responses at three consecutive frequencies counts. It prefers testing from 9 to 20 kHz for earliest detection.
  • Grading scales (official criteria, cohort studies, consensus). CTCAE, the US National Cancer Institute's side-effect scale for cancer trials (version 6.0, 2025), grades hearing by threshold shifts from 1 to 8 kHz or by symptoms and need for a hearing aid. Brock's (1991) and Chang's (2010) scales were developed in children treated with platinum drugs; SIOP Boston was agreed at a 2010 International Society of Pediatric Oncology congress in Boston; TUNE (2014), for adults, adds an average of 8, 10 and 12.5 kHz and patients' complaints.
  • The scales disagree (observational studies, review). On the same audiograms from 333 children with high-risk neuroblastoma, severe hearing loss after cisplatin alone ranged from 8% (Brock) to 47% (CTCAE version 3). A 2016 review of 13 systems found common weaknesses, including insensitivity to small changes and no testing above 8 kHz. In a 2026 study of 74 patients on platinum chemotherapy, TUNE matched patients' reported hearing difficulty in 81% of cases, CTCAE in 73% and ASHA in 68%.
  • Tinnitus (prospective cohort, scales). In a US veterans' study testing 488 people before, during and after treatment, nearly 47% had tinnitus at baseline; cisplatin was linked to 5.53 times the risk of new tinnitus against non-ototoxic drugs, carboplatin 3.75 times and ototoxic antibiotics a borderline 2.81. CTCAE grades tinnitus by symptoms alone, TUNE omits it, and ASHA's criteria are audiometric, though its guideline asks that patients be told to report tinnitus.
  • Programmes (review, guideline). In a 2018 review, all five US programmes it described asked about tinnitus and dizziness, though guidelines did not fully address tinnitus; baseline tests were sometimes missed or done after the first dose. A 2019 guideline for young cancer survivors recommends testing from 1 to 8 kHz from age 6, higher where equipment allows, and strongly recommends audiologist referral for tinnitus, having found only one study of tinnitus risk.

What this means for you

  • Before cisplatin, carboplatin or an intravenous aminoglycoside, ask for a baseline hearing test, ideally reaching above 8 kHz, and mention any tinnitus you already have.
  • Report new or louder tinnitus, muffled hearing or unsteadiness to the treating team without waiting for the next test; do not stop or skip a dose on your own.
  • Hearing that drops over hours to three days needs same-day assessment. Severe vertigo or loss of balance that will not settle is an emergency: call your local emergency number or go to an emergency department.
  • Keep copies of your audiograms; how to read your audiogram explains the chart.

How it connects