Acoustic analysis of hearing aid sound therapy programs

Background: For many healthcare providers, tinnitus and hyperacusis are difficult symptoms to treat. There remains no conclusive cure for either symptom; however, helpful management strategies have been developed utilising counselling and sound therapy. Nowadays, most modern hearing aids have integrated sound therapy as a programable option; although, unlike hearing aid gain characteristics, output verification of sound therapy programs is not common practice. Recent electrophysiological studies suggest that accurately weighting the spectral content of noise in sound therapy could potentially lead to improved outcomes for tinnitus or hyperacusis patients. Methods: To determine if discrepancies exist between sound therapy programing software and hearing aid output, we compared the differences between software intensity settings and hearing aid outputs measured in a Verifit test box for three commonly dispensed manufactures. Results: Results indicate that hearing aid outputs are dramatically different from software readings, and each manufacture output was substantially different from each other. Furthermore, only one hearing aid incorporated audiometric data to normalize noise intensities across frequencies, and two of the aids reached potentially damaging levels. In sum, the data suggests clinical verification of sound therapy programs should be used to ensure the output is appropriate for individual patient’s hearing and consistent with the clinician’s desired approach to tinnitus management.