Table 3. Group means (and SDs between brackets) for P1 and N2 amplitudes and latencies are given for the three speech stimuli used in this study. The infant P1 (positive) response was identified as the most positive point of the waveform in the latency range 100 to 300 ms. Similarly, the negative infant N2 response was defined in the latency range 200 to 600 ms, as the most negative point following the positive P1 response. P1 and N2 amplitudes were defined from baseline to peak. Grand averages can be found in Figure 4.

Speech stimulus	P1 amplitude (µV)	P1 latency (ms)	N2 amplitude (µV)	N2 latency (ms)	No. of data points
/m/	4.3 (2.8)	159 (56)	−4.8 (3.8)	386 (131)	30
/g/	4.0 (2.0)	147 (48)	−3.9 (2.4)	356 (126)	30
/t/	4.2 (2.9)	148 (52)	−5.5 (4.7)	342 (129)	32