As a pharmacist I have access to many drug information sources.
The gold standard drug information source is Micromedex.
Here is what they say on this matter.
3.3.11 Otic Effects (Ibuprofen)
3.3.11.A Ototoxicity
1) Summary
a) TINNITUS and HEARING LOSS are described with the administration of ibuprofen (Prod Info Motrin(R), 1999g).
2) LITERATURE REPORTS
a) The incidence of tinnitus is between 1% and 3% for ibuprofen (Prod Info Motrin(R), 1999g). Ototoxicity usually manifests as tinnitus or hearing loss which is reversible in most cases 24 to 72 hours after stopping the drug. Reports of irreversible ototoxicity are available for aspirin and some non-steroidal anti- inflammatory drugs (NSAIDs).
b) Ototoxicity associated with aspirin is dose and concentration-related but this association is less clear with the NSAIDs. The mechanism, by which this adverse effect occurs, involves inhibition of prostaglandin synthesis and affects primarily the cochlea.