The deterioration of hearing in Ménière's disease is known to be dependent on the individual and to be highly variable. In most cases, however, it leads to moderate hearing impairment. In order to be able to predict deterioration, we used multivariable modelling with a source population of definite cases of Ménière's disease diagnosed according to the latest recommended American Academy of Otolaryngology--Head and Neck Surgery criteria. The records of 205 patients were retrospectively analysed. Their earliest and latest pure-tone air conduction audiograms were used to evaluate the long-term effects of the disease on hearing. The effect of age and the follow-up period were calculated for different frequencies (0.125-8 kHz) and for the pure-tone average over the frequencies 0.5 to 4 kHz (PTA0.5-4 kHz). Deterioration in PTA0.5-4 kHz was approximately 1 dB/year due to the duration of the disease and approximately 0.5 dB/year due to aging. Hearing impairment in Ménière's disease appeared to increase linearly with the duration of the disease for patients < 50 years of age, but in the older subjects the effect of the duration of the disease decreased. Both aging and the duration of the disease affected the hearing level. The duration of the disease did not seem to have any statistically significant effect on the difference between the two ears. The difference that occurred at the onset of the disease remained until presbyacusis in the better ear reached the hearing level of the worse ear. The difference in hearing deterioration between men and women was not significant.