Performance of hearing aids with an induction loop amplification system: laboratory versus classroom setting.

This study was designed to investigate the acoustic response of ten body-type hearing aids when used with an induction loop amplification (ILA) system in the laboratory and in the actual classroom setting. Undesirable frequency response characteristics were discovered in the classroom ILA system used in this study. These consist of a slightly poorer low-frequency response and a deep notch at about 2,500 Hz. Had the frequency response of the classroom ILA system been flat, differences between laboratory and classroom measures would have been minimized. Findings of this study support the practicality of measurement in the classroom of the operating characteristics of ILA systems.