New data on the sound produced by Sphingonotus coerulans corsicus Chopard, 1923 and Truxalis nasuta Linneo, 1758 are given. Oscillograms of both sounds are provided for the first time, as well as their physical characteristics and other aspects of the communication between specimens. For both species sound seems to be a territorial and sexual cue; they have not been observed singing when isolated, as other Acrididae, but always when they are close to or in contact with other individuals. The song of Truxalis nasuta consists of isolated echemes composed of 7-29 syllables lasting about 0.234 seconds. The syllable repetition rate is about 2.2 syllables/sec. The main frequency of emission is between 1 and 10 kHz, with the main peak at 5 kHz. For Sphingonotus coerulans corsicus two different songs have been recorded, one for territorial behaviour and other for courtship. The territorial song consists of isolated syllables lasting about 0.350 seconds with the main frequency between 4 and 8 kHz, with a peak at 7 kHz. The courtship song consists of a syllable produced by the movement of ' the hind legs followed by several microsyllables produced by light movements of the hind legs. The syllable lasts about 0.670 seconds. Sometimes, after the sounds referred to above, the specimens produce a new syllable, always shorter than the first, and with more microsyllables, but always fewer than before. The frequency of this song lies between 3 and 5 kHz, with the main peak at 3 kHz. This communication has been partially supported by the D.G.I.C.Y.T. grant number P889-0448 of the Spanish Government.