Using Biomarkers and Ecological Momentary Assessment to Characterise the Tinnitus Cycle: An Exploratory Study

Abstract

The heterogenous nature of tinnitus makes it difficult to treat in the clinic. This is demanding of clinician and patient resources after therapies are trialled with no guarantee of benefit. Therefore, it is vital to consider the factors that contribute to the individualised experience of tinnitus. Recent literature has elucidated the link between tinnitus and circadian rhythm. Heart rate and sleep have been postulated as potential biomarkers, indicative of tinnitus severity. The outcomes of this study hope to inform future technologies in developing individualised tinnitus treatment. The aim of the study is to investigate whether tinnitus characteristics differ during an individual’s circadian cycle, and whether those changes have any relationship to physiological markers such as heart rate and sleep. It was hypothesised that tinnitus would show stage of day dependence, and that correlations would exist between objective physiological measures and subjective tinnitus perception. Seventeen participants with chronic bothersome tinnitus underwent baseline audiological evaluation and psychoacoustic measurements. Questionnaires were administered to give a subjective measure of the patients’ tinnitus and circadian rhythms. Participants were required to wear a Fitbit smartwatch for a period of seven days during which heart rates and sleeping patterns were recorded and stored. Ecological momentary assessment (EMA) methods were used to characterise patients’ tinnitus experience over this time. Short message service (SMS) notifications were sent on a daily basis after waking, in the middle of waking hours, and before bedtime, during the seven day period. Statistical analysis was conducted on the results to investigate differences in tinnitus severity between the three stages of day, and correlations between tinnitus severity and physiological measures. Analysis of variance (ANOVA) results showed a statistically significant difference between tinnitus loudness, annoyance and ignorability between the three stages of day. Tinnitus comfort did not change depending on the stage of day. No statistically significant correlations were found between heart rate, sleep times and self-rated severity of tinnitus. Several other incidental findings related to biophysiological markers and baseline data open avenues for further investigation. This study has proven the concept of using biological sensors alongside EMA in the evaluation of tinnitus is a promising candidate for clinical application.