The callings songs of five species from three genera of South African pygmy bladder cicadas are analyzed. The call of each species has a distinct temporal pattern and frequency spectrum. The songs are of significantly lower frequency than would be predicted based on body mass or body length. Comparison of bladder cicada calls from Australia and South Africa show similar lower than predicted frequencies in species of independent evolutionary origin. The inflated abdomen found in these cicadas appears to be a convergent adaptation to permit more efficient song production at lower carrier frequencies that increase the distance the songs will travel.