Distinct and dissociable signatures of hypersensitivity (hyperacusis) and phantom perception (tinnitus) revealed through evoked brain responses to intensity deviants

<p dir="ltr">Despite the long-known overlap between tinnitus and hyperacusis prevalences and aetiologies, hyperacusis has often been overlooked as a potential confounding factor in tinnitus research or as an independent condition of interest. Given that both tinnitus and hyperacusis involve abnormal sound intensity processing, either via false inference of input or over-representation, intensity change encoding is a logical target for investigation.</p><p dir="ltr">This rigorously-matched (by age, sex and peripheral hearing profiles) factorial study compared four groups: tinnitus, hyperacusis, both, and controls (n=21 each), using a roving intensity oddball paradigm and EEG to measure Mismatch Negativity (MMN), P50, N100 and P200 auditory evoked responses.</p><p><br></p><p dir="ltr">Trigger structure used for data collection:</p><p dir="ltr">cond_labs = {'Std Low Con','Std High Con','Std Low Tin','Std High Tin', 'Dev Down Con','Dev Up Con','Dev Down Tin','Dev Up Tin', 'Durdev Low Con','Durdev High Con','Durdev Low Tin','Durdev High Tin'};</p><p><br></p><p dir="ltr">conditions = {'10111','10121','10211','10221', '10112','10122','10212','10222', '20111','20121','20211','20221',};</p><p><br></p><p dir="ltr">Definitions: Std = standards, dev = intensity deviants, durdev = duration deviants, low = quiet stimulus. high = loud stimulus, tin = tinnitus frequency, con = control frequency</p>