Brief Answer:
No need to worry just go for otoscopic examination

Detailed Answer:
Hi Mam,
I have gone through your query and it suggests that your husband most probably suffering from the ototoxicity mainly vestibulotoxicity if he has perforated ear drum or traumatic injury to the auricular branch of vagus nerve if he has intact ear drum.
I suggest you that your husband should go for
1. Otoscopic examination of the ear to check the status of the external auditory canal and ear drum.
2. Fistula test to rule out any fistula in the ear drum.
3. Tunning fork test to check the status of hearing.

Avoid putting water, oil, ear bud, nitrogen/ hydrogen peroxide to avoid further damage to the ear.

Thanks

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