1) Toxic 
having a deleterious effect upon the eighth nerve, or upon the organs of hearing and balance.
Having a deleterious effect upon the eighth nerve or upon the organs of hearing and balance. ... (18 Nov 1997) ... 
(o´to-tok″sik) having a damaging effect upon the eighth cranial (vestibulocochlear) nerve or on the organs of hearing and balance.
Type: Term Pronunciation: ō′tō-tok′sik Definitions: 1. Relating to ototoxicity.
[adj] - toxic to the organs of hearing or balance or to the auditory nerve
ototoxic 1. Poisonous to the ear; applied particularly to drugs which are liable to cause such damage. 2. Having a detrimental effect on the organs of hearing.
adjective toxic to the organs of hearing or balance or to the auditory nerve; `some drugs are ototoxic`
having a harmful effect on the organs or nerves concerned with hearing and balance.