High-frequency pure-tone audiometry is critical for detection of aminoglycoside-induced HL. In the Swiss population, screening for mutations in the 12S rRNA gene, before the initiation of aminoglycoside therapy, is not supported by this limited study. A larger multicenter and multicultural study is warranted to more definitively address this critical clinical issue.

Specific recommendations from the American Speech-Language Hearing Association (1994) exist for the audiometric surveillance of patients receiving aminoglycoside therapy. However, these recommendations are not based primarily on test-retest repeatability in often seriously ill patients. The probability of ototoxicity is very low during the first three days of aminoglycoside therapy, and significant threshold shifts can be assumed to represent a false-positive result. Baseline thresholds were measured in 28 patients before or not later than 24 h after the beginning of aminoglycoside therapy. These measurements were repeated in 22 patients during the first three days of the drug administration. Three out of 22 patients fulfilled the American Speech-Language-Hearing Association’s (1994) criteria for cochleotoxicity making up a false-positive rate of 13%. In actual patients, the false-positive rate of audiometric surveillance during ototoxic drug administration may be substantially higher than in healthy subjects when these criteria are used.