Analysis of reaction time at Fc.

A repeated-measures ANOVA on RT was first performed, with frequency relative to Fc (Fref, Fc-1/8, Fc and Fc+1/8) and rehabilitation time-course as within-subject factors. No significant difference was found across frequencies (F(3,7978)=1.230, p=0.30). However, RTs were significantly shorter 3 months after HA fitting (F(1,7978)=22.409, p<10-4) (Figure 1). No significant interaction was found between these two factors (F(3,7978)=0.491, p=0.69).

Figure 1: Mean RT recorded around Fc (Fc-1/8; Fc; Fc+1/8) before and three months after auditory rehabilitation for the 5 subjects with a hearing aid.

fref is the reference frequency and was located one octave before Fc. Around Fc, RTs were significantly shorter at 3 months post-rehabilitation. Error bars represent standard errors.

As each frequency was tested about 200 times in each subject, a two-factor ANOVA (rehabilitation time-course and frequency relative to Fc) was also performed individually. In every subject, reaction times were significantly different after auditory rehabilitation (subject F.P.: F(1.1543)=16.99, p<10-4; subject D.P.: F(1,1603)=12.17, p<10-3; subject Y.M.: F(1,1547)=59.2, p<10-4; subject A.D.: F(1,1638)=32.39, p<10-4; subject C.V.: F(1,1619)=49.40, p<10-4). However, no frequency effect or interaction was observed. In subjects F.P., Y.M. and C.V., RTs were shorter at 3 months post-rehabilitation, whereas they were longer in subjects D.P. and A.D (Figure 2). In the control subject S.G., RTs were significantly shorter at three months post-rehabilitation (F(1,1597)=15.83, p<10-4).

Figure 2: Alteration in reaction time around Fc (Fc-1/8; Fc; Fc+1/8) and bDLF (bDLF-1/8; bDLF; bDLF+1/8) before and three months after auditory rehabilitation in each subject.

Note that in every subject, RTs were different before and 3 months after rehabilitation: they improved in subjects F.P., Y.M. and C.V. and lengthened in subjects D.P. and A.D. Bottom right: RTs for the control subject S.G..