The Effect of Digital Phase Cancellation Feedback Reduction Systems on Amplified Sound Quality

The effect of feedback reduction (FBR) systems on sound quality recorded from two commercially available hearing aids was evaluated using paired comparison judgments by 16 participants with mild to severe sloping hearing loss. These comparisons were made with the FBR systems on and off without audible feedback and while attempting to control for differences in gain and clinical fitting factors. Wilcoxon signed rank test analyses showed that the participants were unable to differentiate between signals that had been recorded with the FBR systems on and off within the same hearing aid. However, significant between-instrument differences in sound quality were identified. The results support the activation of the FFT-phase cancellation FBR systems evaluated herein without concern for a noticeable degradation of sound quality. Se evaluó el efecto de los sistemas de reducción de la retroalimentaciñn (FBR) sobre la calidad del sonido registrado por medio de dos auxiliaries auditivos disponibles comercialmente, utilizando juicios de comparación en pares, de 16 participantes con una hipocusia leve a moderada de pendiente pronunciada. Estas comparaciones se realizaron con los sistemas FBR apagados y encendidos, sin retroalimentación audible y tratando de controlar las diferencias en cuanto a ganancia y a factores clínicos de adaptación. Los análisis de pruebas de rango certificados por Wilcoxon mostraron que los participantes no podian diferenciar entre señales que habian sido registradas con los sistemas de FBR encendidos o apagados dentro del mismo auxiliar auditivo. Los resultados apoyan la activación de los sistemas de FBR de cancelación de fase FFT, aqui evaluados, sin preocupaciones por una degradación identificable en la calidad del sonido.

Key Words

Feedback reduction system - hearing aid - paired comparison - sound quality