Notched Noise Therapy for Suppression of Tinnitus

Tinnitus ("ringing in the ears") has long been a problem for Veterans. The problem continues to escalate due to high levels of noise in the military, and because tinnitus often is associated with traumatic brain injury and post-traumatic stress disorder. In spite of limited research support, sound-based (acoustic) therapies are most often used for tinnitus intervention, and increasing numbers of commercial devices are becoming available that offer various acoustic-stimulus protocols. The proposed study will provide evidence from a randomized controlled trial comparing effects of acoustic-stimulus methods that are purported to suppress tinnitus and/or reduce its functional effects. The study will focus on methods with the strongest scientific rationale, i.e., noise that is notched around the predominant tinnitus-frequency region. Special ear-level devices will deliver these acoustic-therapy protocols that are purported to modify tinnitus-related neural activity. The study will follow a study recently completed by the applicant that provides preliminary evidence supporting this method.

Inclusion Criteria: Candidates must meet the following inclusion criteria to qualify: * Veteran * no active middle-ear disease * at least one air conduction hearing threshold of 40 dB HL or worse in each ear between .25-8 kHz as measured at the first study visit * unilateral or bilateral constant tinnitus * index score on the Tinnitus Functional Index (TFI) of at least 25 (out of a maximum score of 100) * a score of 24 or higher on the Mini Mental State Exam (MMSE) * a tinnitus pitch match between 2-10 kHz (and achieve desired level of precision as described below in 3.3 Study Procedures, Tinnitus Psychoacoustic Assessment) * demonstrates understanding of the requirements of the study * motivated and capable of participating (including ability to communicate in English) Exclusion Criteria: The following exclusion criteria will be used: * two or more hearing thresholds exceeding 70 dB HL * significant conductive hearing loss-defined as an air-bone gap of 15 dB at more than two frequencies in one ear, or an air-bone gap greater than 15 dB at any one frequency * suspicion of secondary (somatic) tinnitus, Meniere's disease, or tinnitus potentially related to temporo-mandibular disorder or whiplash (any of which can be ruled out with an examination by an appropriate physician) * any mental, emotional, or health conditions that would preclude full study participation