Acute Comparison of Mild-Gain Hearing Aid Approaches in an Adult With Mild Traumatic Brain Injury and Long-Term Effects of Mild-Gain Amplification on Speech Perception in Noise and Self-Reported Hearing-Related Disability, Hyperacusis, and Quality of Life.

Objective: This report documents the effects of hearing treatment in an adult with a history of mild traumatic brain injury (mTBI) and normal peripheral hearing acuity.

Design: This report details a case study of a 26-year-old female with a history of mTBI.

Study Sample: A 26-year-old female with a history of mTBI presented with auditory symptoms including tinnitus, hyperacusis, listening fatigue, and speech-in-noise (SIN) difficulties despite diagnostic audiological findings showing normal peripheral auditory function and suprathreshold SIN performance within the normal range. The patient was fit with premium-level receiver-in-the-canal (RIC) hearing aids (HAs) using several different mild-gain fitting approaches involving wide dynamic range compression (WDRC) or linearized gain. A combination of objective and subjective methods was utilized to guide clinical decision making on the fitting approach and to verify/validate treatment outcomes.

Results: Despite no difference in acutely aided SIN performance between the WDRC or linearized fitting approaches, the patient expressed a clear preference for the HA fitting approach involving application of 2-10 dB of shaped linearized gain > 1.5 kHz for soft, medium, and loud input levels (with greatest gain applied at 3-4 kHz). These settings were preferred in terms of loudness and sound quality even compared to the WDRC fitting approaches previously reported in literature. This fitting approach was verified and validated by SIN testing showing improved performance in the aided condition, as well as high levels of self-reported benefit and satisfaction, reduction in self-reported hearing handicap, reduction in sound sensitivity, and enhanced quality of life with HAs.

Conclusions: Results add to the growing body of evidence supporting the benefits of mild-gain HAs for adults with mTBI and self-reported SIN deficits despite normal hearing acuity. Results also support the importance of using a combination of measures (e.g., SIN testing, patient report, outcome questionnaires) to guide the HA fitting process and to verify/validate treatment outcomes. Although findings were derived from a single case study and should be interpreted with caution, the patient's preference for a shaped linearized mild-gain approach is noteworthy. There exists a lack of clinical guidelines and prescriptive fitting methodology for fitting HAs in mTBI adults with SIN difficulty despite normal peripheral hearing acuity. Future research should systematically compare WDRC versus linearized gain approaches of fitting in this population to develop a clinical methodology for HA fitting and optimize outcomes in this special subpopulation.