Assessing Auditory Processing Deficits in Tinnitus and Hearing Impaired Patients with the Auditory Behavior Questionnaire.

Background and Purpose: Auditory processing disorders (APD), tinnitus and hearing loss (HL) are typical issues reported by patients in audiologic clinics. These auditory impairments can be concomitant or mutually excluding. APD are not necessarily accompanied by significant HL, whereas many adults exhibit peripheral HL and typical cognitive deficits often associated with APD. Since HL, tinnitus and APD affects to several parts of the ascending auditory pathway from the periphery to the auditory cortex, there could be some interrelationship between them. For instance, tinnitus has been reported to degrade the auditory localization capacity. Tinnitus is believed to be triggered by deafferentation of normal peripheral input to the central auditory system. This peripheral deficit can be accompanied by HL or not, since a type of permanent cochlear damage (thus deafferentation) without an elevation of hearing thresholds might persist. Therefore, a combined study of APD, tinnitus and HL on the same cohort of patients can be audiologically relevant and worthy. Methods: Statistical analysis is applied to a cohort of 305 patients attending an audiology clinic in Madrid (Spain). This group of patients is first categorized in four subgroups, namely, HLTG (with tinnitus and HL), NHLTG (with tinnitus and without HL), HLNTG (with HL but no tinnitus), and NHLNTG (neither tinnitus nor HL). The statistical variables include Age, Average Auditory Threshold (ATT), for assessing HL, Tinnitus Handicap Inventory (THI), for measuring tinnitus, and a new 25-item Auditory Behavior Questionnaire (ABQ), for scoring APD. Factor analysis is applied to arrange these items into 4 subscales. The internal consistency reliability of this ABQ is confirmed by calculating Cronbach's coefficients α. The test-retest reliability is assessed by the intraclass correlation coefficients, ICC. Statistical techniques applied to the data set include descriptive analysis of variables and Spearman rank correlations (ρ) between them. Results: Overall reliability of ABQ is confirmed by an α value of 0.89 and by an ICC of 0.91. Regarding the internal consistency reliability, the four subscales prove a fairly good consistency with α coefficients above 0.7. Average values of statistical variables show significantly lower age of patients with tinnitus and no HL, which can provide a cue of noise overexposure of this segment of population. These younger patients show also decreased ABQ and similar THI in comparison with patients in the other subgroups. A strong correlation (ρ = 0.63) was found between AAT and Age for the HLNTG subgroup. For the HLTG subgroup, a moderate correlation (ρ = 0.44) was found between ABQ and THI. Conclusion: The utilized questionnaire (ABQ), together with AAT and THI, can help to study comorbid hearing impairments in patients regularly attending an audiological clinic.