The use of pure-tone audiometry in the assessment of gentamicin auditory toxicity.

The results of previous studies of gentamicin auditory toxicity have depended largely on the criteria set for a significant change in hearing threshold. This paper proposes a design for future studies of aminoglycoside toxicity based on an investigation of factors other than aminoglycoside therapy which may influence the measurement of hearing threshold. Audiometry can be performed reliably in a ward but a patient's condition has both temporary and permanent effects on hearing threshold. Ototoxicity cannot be detected by assessing hearing after aminoglycoside therapy. However, an audiogram taken at the start of treatment may be misleading if the patient is seriously ill. Permanent hearing loss may be due to factors other than aminoglycoside therapy so that future studies must be controlled.