Late auditory evoked potentials in elderly long-term hearing-aid users with unilateral or bilateral fittings

► P2 amplitude reveals a frequency-specific acclimatization effect in the aided ear. ► P2 amplitude is larger at higher and smaller at lower frequencies in the aided ear. ► P2 amplitudes are enhanced in unilaterally fitted hearing-aid users. ► Enhanced P2 amplitudes could be a correlate of more effortful auditory processing.