Changes in tinnitus and physiological biomarkers of stress in response to short-term broadband noise and sounds of nature

Abstract

BackgroundTinnitus is the perception of sound when no external sound source is present. In some cases, this perception coincides with, or results in, stress. Tinnitus-related distress has been associated with increased levels of cortisol and elevated levels of sympathetic tone. Our primary hypothesis was that short-term sound exposure would reduce tinnitus perception and various physiological measures of stress. A secondary hypothesis was that a self-selected nature sound would reduce physiological markers of stress more than broadband noise. MethodsTwenty-one participants with constant bothersome tinnitus underwent an audiological assessment. Measurements of blood pressure, heart rate, salivary cortisol and cortisone concentrations, and tinnitus ratings were carried out three times: prior to and, in a counterbalance order, after 30 min of broadband noise and after 30 min of a self-selected nature sound (from: ocean waves, stream, rain or shower sounds). ResultsFindings revealed significant reductions in blood pressure measurements following broadband noise. None of the other stress measures demonstrated a statistically significant change. Both broadband noise and nature sounds elicited significant improvements in ratings of tinnitus. ConclusionsWhile both sound types had a positive impact on many dimensions of tinnitus, only the broadband noise was associated with a reduction in blood pressure. These results are consistent with a complex interaction between sound and tinnitus and suggest a multifactorial basis to sound therapy that includes a reduction in arousal.