Context: According to the National Institutes of Health, in 2011, chronic pain affected from approximately 10% to >50% of the adult population in the United States, with a cost of $61 billion to US businesses annually.
Objective: The pilot study assessed the effects that an external, audio, neural stimulus of theta binaural beats (TBB) had on returning the brain neurosignature for chronic pain to homeostasis.
Methods: The quantitative, experimental, repeated-measures crossover study compared the results of 2 interventions in 2 time-order sequences. An a priori analysis indicated a sample size of 28 participants was needed for a 2-way repeated-measures analysis of variance (ANOVA).
Setting: The study was conducted in Richmond, VA, USA, with participants recruited from the financial sector.
Participants: Thirty-six US adults with various types of chronic pain, and with a median age of 47 y, ranging in ages from 26-69 y, participated in the study. The study experienced 4 dropouts.
Intervention: Participants listened to 2 recordings-one using TBB at 6 Hz (TBB intervention) and one using a placebo of a nonbinaural beat tone of 300 Hz (sham intervention) for 20 min daily. Both interventions lasted 14 successive days each, with some participants hearing the TBB intervention first and the sham intervention second and some hearing them in the reverse order. Participants listened to the interventions via a Web site on the Internet or via a compact disc. Interviews were conducted either in person or telephonically with e-mail support.
Outcome measures: Using the West Haven-Yale Multidimensional Pain Inventory (MPI), potential changes in perceived severity of chronic pain were measured (1) at baseline; (2) after the first test at 14 d, either TBB or sham intervention; and (3) after the second test at 28 d-either TBB or sham intervention. The analysis compared the average mean for pretest and first and second posttest scores.
Results: The analysis indicated a large main effect for the TBB intervention in reducing perceived pain severity, P<.001 (F2,60=84.98, r=0.74). Although the TBB and the placebo interventions both reduced the pain scores, a post hoc Bonferroni correction that compared pairs of MPI scores found a 77% larger drop in the mean for the TBB intervention, from M=4.60 at pretest to M=2.74 at the end of both TBB periods than in the mean for the sham intervention, with a change from M=4.60 at pretest to M=4.17 at the end of both sham periods.
Conclusions: The results supported the hypothesis that an external audio protocol of TBB was effective in reducing perceived pain severity for participants.