Fig. 3. Effects of experimental treatments on rev displays. Within treatment pairs (control and experimental), peak intensities were normalized to the maximum intensity produced. Graphs show average dB differences for each treatment type. (A) Palpal treatment. Experimental treatment attenuated high frequencies (**P<0.001, paired t-test). No significant difference was observed for low frequencies (ns, not significant). (B) Abdominal treatment. Experimental treatment attenuated low frequencies (*P<0.05, paired t-test). No significant difference was observed for high frequencies (ns). (C) Palpal and abdominal treatment. Experimental treatment attenuated both low and high frequencies (**P<0.001, paired t-test).