gms | German Medical Science

To showcase aided benefits, we built a prototype hearing aid demonstrator consisting of circumaural headphones, two microphones on each side, and a miniaturized computer. Various preset gain settings allow people to experience potential aided benefits easily. A comprehensive evaluation was performed indicating that the performance of the prototype is close to that of a state-of-the-art commercial device and that it provides significant benefit compared to unaided listening. Furthermore, during a public outreach event, the demonstrator was used to showcase hearing aid benefits and raise awareness for one’s own hearing difficulties [1]. Beside showcasing aided benefits, we see an interesting use case also in clinical practice.

Research question: Can a hearing aid demonstrator be used to guide clinical hearing aid treatment?

Methods: The guidelines for hearing aid provision in Germany are considered. 20 experienced hearing aid users were invited. Speech intelligibility was tested with the Freiburger monosyllabic speech test unaided, with own hearing aids, and with the hearing aid demonstrator in quiet at 65 and 55 dB SPL and in noise (S0°N0°, S65N60). Moreover, maximum speech intelligibility was measured by increasing the presentation level of speech in quiet. This value, often referred to as mEV (maximales Einsilberverstehen), is an important reference and target value when fitting hearing aids in Germany.

Results: In all conditions, statistically significant correlations and no statistically significant differences were found between speech intelligibility with the participants’ own hearing aids and with the hearing aid demonstrator. The mEV was also statistically significantly correlated with speech intelligibility measured with the participants’ own hearing aids in all conditions. However, the correlation was lower and the root mean squared error (RMSE) higher when mEV instead of the outcome with the hearing aid demonstrator was used as a predictor for speech intelligibility with the participants' own hearing aids.

Conclusion: With the hearing aid demonstrator, achievable benefits with hearing aids can be easily illustrated both in clinical practice and at public events. Knowledge about expectable benefits can be useful to verify and check hearing aid fittings and to convince patients to try out commercial hearing aids. Further, speech intelligibility measurements with the hearing aid demonstrator provide a simple means to obtain a target for hearing aid fitting, which may be more appropriate than the mEV.

Figure 1 [Fig. 1]