If you read the cautions that came with your meds, this should explain all the possible side effects. Ethambutol can affect the eyes. Rifampin and Azithromycin can affect the hearing.
If you notice any changes, stop the meds, call your pulmonologist and see the audiologist or ophthalmologist right away.
Also, it should have been suggested that you get tested every 6 months while taking the big 3.