FM systems as a treatment for CAPD

Abstract

amplification, despite adequate gain. Unaided tests results showed that performance on the SSI at 0 MCR was 0% bilaterally. At +10 MCR, performance was 80% in the right ear and 46% in the left. This closely matched her word-recognition performance of 70% in the right ear and 46% in the left. When fitted with an FM system, her SSI performance at -10 MCR was 100%, whereas with a hearing aid (right ear only) it reached normal limits only in quiet. The patient was satisfied with the FM system and reported beneficial changes in her lifestyle. EVIDENCE IS ENCOURAGING Although conclusions based on case studies alone should be drawn with caution, preliminary evidence for this treatment is very encouraging. Most patients, regardless of age, received considerable benefit from an FM system, as determined by SSI performance. It is extremely interesting that central auditory processing shows such large improvements following this treatment. Patients whose performance was extremely poor without an FM system achieved almost 100% performance with FM. This result warrants consideration of this treatment in patients with persistent auditory processing difficulties. For patients with both peripheral and central hearing loss, hearing aids alone will probably not improve signal-to-noise ratio enough to overcome the central deficit. In the cases described above, increases in SSI performance were observed only when the FM system was used, not with hearing aids alone. Directional technology has improved since these cases were reported, but recent research suggests that, when both treatments are considered separately, directional microphones in hearing aids provide less benefit than FM systems. 1 Hearing aids are necessary for patients who show both a peripheral and a central hearing loss. However, supplementing them with an FM system may provide a benefit not otherwise attainable in this population.