An investigation of selected factors affecting feedback in high gain hearing aid fittings

• Main Author: Hoover, Hal N.
• Other Authors: Hemeyer, Thomas F.
• Format: Others
• Published: 2011
• Subjects: Hearing aids.
• Online Access: http://cardinalscholar.bsu.edu/handle/handle/181749; http://liblink.bsu.edu/uhtbin/catkey/280179

The purpose of this investigation was to compare three typical modes of fitting hearing aids with respect to the amount of maximum gain which could be obtained before the onset of acoustic feedback. A group of 15 children and a group of 15 adults were used. Each subject was fitted with: (1) a regular ear level hearing aid, (2) a body hearing aid in the conventional mid-torso position, (3) a body hearing aid worn high and to one side of the torso, as is commonly done in binaural body hearing aid fittings. The hearing aid volume controls were increased to a point just prior to the onset of feedback. Once this procedure had been completed for all three hearing aid fittings the high frequency average gain was measured on Bruel and Kjaer equipment.The results indicated that there was no significant difference between the gain values for the two groups, adult versus children. There was, however, a significant difference between the gain values of the three test positions. The mid-torso position achieved the highest gain, the shoulder position was the next highest, and the ear level position achieved the least gain. There was a significant interaction effect between groups (adult, children) and placement (mid-torso, shoulder, ear level).