Can the impact of hearing impairments be modelled?

The effects of two simulated hearing impairments (presbyacusis) on speech perception were investigated in two groups of normally hearing subjects (30 and 48 subjects, respectively). Eight patients with presbyacusis with similar hearing impairment to those in the latter simulation served as the clinical material. Word recognition scores were measured in quiet and in cocktail party noise (S/N + 18 dB and + 12 dB). The recognition scores deteriorated in the less favourable listening conditions. Somewhat surprisingly, the hearing impaired subjects showed better word recognition scores in quiet and especially in moderate noise. Subjective complaints on speech perception difficulties in noise on a visual analogue scale behaved quite logically; the hearing impaired subjects' subjective experiences were no milder than those of the normally hearing during the simulation. The better results in word recognition shown by the hearing aid candidates may be explained by habituation to the hearing impairment.