Auditory neurophysiology reveals central nervous system dysfunction in HIV-infected individuals.

OBJECTIVE: To test the hypothesis that human immunodeficiency virus (HIV) affects auditory-neurophysiological functions. METHODS: A convenience sample of 68 HIV+ and 59 HIV- normal-hearing adults was selected from a study set in Dar es Salaam, Tanzania. The speech-evoked frequency-following response (FFR), an objective measure of auditory function, was collected. Outcome measures were FFRs to the fundamental frequency (F0) and to harmonics corresponding to the first formant (F1), two behaviorally relevant cues for understanding speech. RESULTS: The HIV+ group had weaker responses to the F1 than the HIV- group; this effect generalized across multiple stimuli (d = 0.59). Responses to the F0 were similar between groups. CONCLUSIONS: Auditory-neurophysiological responses differ between HIV+ and HIV- adults despite normal hearing thresholds. SIGNIFICANCE: The FFR may reflect HIV-associated central nervous system dysfunction that manifests as disrupted auditory processing of speech harmonics corresponding to the first formant.