Validation of a Mobile Device for Acoustic Coordinated Reset Neuromodulation Tinnitus Therapy

Background: Sound-based tinnitus intervention stimuli include broad-band noise signals with subjectively adjusted bandwidths used as maskers delivered by commercial devices or hearing aids, environmental sounds broadly described and delivered by both consumer devices and hearing aids, music recordings specifically modified and delivered in a variety of different ways, and other stimuli. Acoustic coordinated reset neuromodulation therapy for tinnitus reduction has unique and more stringent requirements compared to all other sound-based tinnitus interventions. These include precise characterization of tinnitus pitch and loudness, and effective provision of patient-controlled daily therapy signals at defined frequencies, levels, and durations outside of the clinic. Purpose: The purpose of this study was to evaluate an approach to accommodate these requirements including evaluation of a mobile device, validation of an automated tinnitus pitch matching algorithm and assessment of a patient's ability to control stimuli and collect repeated outcome measures. Research Design: The experimental design involved direct laboratory measurements of the sound delivery capabilities of a mobile device, comparison of an automated, adaptive pitch-matching method to a traditional manual method and measures of a patient's ability to understand and manipulate a mobile device graphic user interface to both deliver the therapy signals and collect the outcome measures. Study Sample: This study consisted of 5 samples of a common mobile device for the laboratory measures and a total of 30 adult participants: 15 randomly selected normal-hearing participants with simulated tinnitus for validation of a tinnitus pitch matching algorithm and 15 sequentially selected patients already undergoing tinnitus therapy for evaluation of patient usability. Intervention: No tinnitus intervention(s) were specifically studied as a component of this study. Data Collection and Analysis: Data collection involved laboratory measures of mobile devices, comparison of manual and automated adaptive tinnitus pitch matching psychoacoustic procedures in the same participant analyzed for absolute differences (t test), variance differences (f test), and range comparisons, and assessment of patient usability including questionnaire measures and logs of patient observations. Results: Mobile devices are able to reliably and accurately deliver the acoustic therapy signals. There was no difference in mean pitch matches (t test, p > 0.05) between an automated adaptive method compared to a traditional manual pitch-matching method. However, the variability of the automated pitch matching method was much less (f test, p < 0.05) with twice as many matches within the predefined error range (+/- 5%) compared to the manual pitch-matching method (80% versus 40%). After a short initial training, all participants were able to use the mobile device effectively and to perform the required tasks without further professional assistance