Gapinducedpie-pulseinhibition(Gap-PPI)ofacousticstartlereflexhasbeenusedasameasurementoftinnitusinanimalmodels.However,whetherthistestissensitivetodetecttinnitusinhumansisstillunclear.Basedonthetestingprocedureusedinanimalstudies,ahumansubjecttestingmethodwasformulatedandconductedtoinvestigateifasimilarresultcouldbefoundintinnituspatients.Audiologicandtinnitusassessmentsandacousticstartlereflexmeasurementswereperformedonseventinnitussubjectsandnineagematchedsubjectswithouttinnitus.TherewasnosignificantdifferencefoundbetweenthecontrolandtinnitusgroupontheGap-PPlacrossthefrequenciesevaluated.Theamplitudeofthestartleresponseinthetinnitusgroupwithnormalhearingthresholdswassignificantlyhigherthanthecontrolgroupandthosewithtinnitusandhearingloss.Thispreliminaryresultsuggeststhathyperexcitabilityinthecentralauditorysystemmaybeinvolvedintinnitus.Therewasnocorrelationbetweenhearingthresholdsandtheincreasedamplitudeofstartleresponse.
