Abstract
This project investigated the maturation of P1 of 32 native Arabic speaking children; all had a primary diagnosis of SLI. The study group had a mean age 60.25 (±6.4) months (range 50–80 months) at the time of the primary diagnosis. The control group consisted of 69 children matched for age, language level and academic skills, with no history of language disability. 30 children of the SLI group were re-examined 28 months after primary diagnosis. The test battery included basic audiological evaluation and P
1/N
2 complex evoked by speech syllable /da/ and presented binaurally through sound field.
Stepwise regression analysis of variables showed significant shortening of P1 peak latency in both control and SLI group showed proportional to the natural logarithm of the chronological age (
r
=
−.414 &
r
2
=
.418). P1 peak amplitude showed significant decrease in amplitude in both control and SLI group proportional to the square of the chronological age (
r
=
−.375 &
r
2
=
.140). However, no significant difference could be detected between the SLI group and the control group as regards P1 peak latency and peak amplitude. Moreover, the study showed no statistical significant difference between the control group and the study group as regards the correlation between P1 and language age (P1 latency
t
=
.153, while significant
t
=
.879 and P1 amplitude (
t
=
−.37) significant
t
=
.712). The partial correlation coefficient was .04 for P1 latency and .088 for P1 amplitude.
Considering the heterogeneity of the SLI group, P1 peak amplitude and peak latency may be valuable to follow up the maturation of the auditory system on individual basis rather than for differential diagnosis of SLI patient from normal. P1 does not show dramatic developmental change in the age range 5–10 years to be used clinically. Further researches are needed to standardize statistical method for analyzing P1 waveform.