Mean durations of individual call types in different categories between control and REMSR groups on various developmental days.

The values are presented in msec and are tabulated as median (minimum, maximum) in bracket. NF stands for calls that were ‘not found’. A denotes category consisting of flat calls; B having upwards (i), downwards (ii), U shaped (iii), and inverted-U shaped (iv); C is sum of 2 and 3 syllable and D contains wave (i) and complex calls (ii). The significant changes on comparison of calls between control and REMSR are depicted in ‘*’. The level of significance is p<0.05.