The Effects of Silicone and Acrylic Ear Mold Materials on Outer Ear Canal Resonance Characteristics.

OBJECTIVES The aim of this study is to investigate the effects of earmolds made of silicone and acrylic on outer ear canal resonance characteristics in terms of resonance frequency and amplitude measured in a hearing aid fitting. MATERIALS AND METHODS Outer ear canal resonance frequencies and amplitudes in open ears and those measured with silicone and acrylic ear molds were obtained from 30 participants between the ages of 20 and 25 years (average age, 22.0 years; 18 females and 12 males) with a real ear gain measurement. To observe the changes depending on probe tube placement, test-retest variation was investigated in 10 participants before the study. RESULTS There was no statistically significant difference between open ear canal resonance frequencies and those measured with silicone and acrylic earmolds (p>0.05). the silicone earmold resonance amplitude values were statistically significantly lower than the open ear canal resonance amplitudes when compared to those of the acrylic earmolds (p<0.05). CONCLUSION Depending on the changes occurring in outer ear resonance features as a result of earmold materials used in hearing aid fittings, the application of earmolds should be done by experienced specialists.