Intelligibility of speech transduced via classroom-installed FM and conventional audio induction loop amplification systems.

This study was designed to investigate the intelligibility of speech transduced through a classroom-installed FM system and a conventional induction loop amplification (ILA) system and to examine the applicability of an FM adapter when used with commercially available hearing aids. Findings indicate that speech reproduced via the FM system is significantly better than that of the conventional audio induction loop used in this study. It seems likely that the irregular high-frequency response of the ILA system was responsible for this difference. When an FM adapter was used in conjunction with body-type hearing aids, the frequency response of the telecoil along with the positioning of the adapter determine the total performance of the aid.