I've had tinnitus for 20 years, from unknown causes, and seems to have worsened from treatments, including Hearing, but many other things medically, can also be the cause, including trauma, ototoxic drugs like Cisplatin, up to 30% of patients in some studies, Carboplatin 1%, and rarely with oxaliplatin, including some antibiotics and other medications can cause ototoxicity. Seems Cisplatin tinnitis occurs from infusions with a higer dose of 50mg, and maybe more when cumulative doses reaches 300mg. It's unclear wether it's permamnt or not, and can be a problem for months, years.

As mentioned, there are apps you can use for "white noise." I use "Sleepbug" to block out the crickets, which seems worse when it's quiet, especially at night. A fan, and or an air conditioner works well too. If it's dose dependent, I don't know if they can reduce the dosage, change the chemo, and or slow down the infusion rate to reduce the toxicity. Cytotoxity, drinking cold water, chewing ice during infusion, helps with mucocitis, hand and foot syndrome, neuropathy, hair loss with other chemo's, like Taxotere, 5-FU, but unsure if it will help with Cisplatin, which kills the hair cells in the inner ear, cochlear, resulting in tinnitus, hearing loss, and can be worse in prior or current head and neck irradation with Cisplatin. Drinking enough water to help flush the kidneys too of the cytocic drugs, as impaired kidney's can also cause tinnitis.

I heard of other supplements that may help, like Gingko Biloba, but check with your doctor. Maybe see an audiologist too, and assume you didn't have any baseline testing before treatment? Don't worry I never did either, and still haven't had my hearing checked, eyes, yes.

I hope this helps.