Long-term effects of hearing aids on word recognition scores

The purpose of this study was to retrospectively examine how monaurally fitted hearing aids affected word recognition scores in patients with bilateral symmetric sensorineural hearing loss.

Sixty-six patients from 2 separate institutions were included in this study. In addition to having bilateral symmetric sensorineural hearing loss due to presbycusis, each patient had to have worn a single hearing aid for at least 5 months and have valid pre-aid and post-aid audiograms. Word recognition scores were analyzed with a table of confidence levels generated by Thornton and Raffin that determined the probability of differences between word recognition scores.

Hearing aids did not improve or preserve word recognition scores to the degree that has been previously reported in the literature. The unaided (control) ear demonstrated a decrease in word recognition scores over time, as was expected from previous studies. The aided ears demonstrated a similar decline in word recognition scores when compared to the unaided ears. When the conventional confidence level of 0.05 was used, the aided ears showed no advantage over the unaided (control) ears.

These findings are not consistent with the acclimatization first reported by Silman et al in 1993. Such a discrepancy in the results calls for further studies to evaluate just how effective unilateral hearing aids are in patients with bilateral symmetric sensorineural hearing loss.