Fig. 3

a Melodic range spectrogram of the sound used for the sonification of the ground contact for G1 (base frequency of 150-250 Hz) and (b) melodic range spectrogram of the sound used for the sonification of the ground contact for G2 (base frequency of 95-112 Hz). Only one channel is shown at a time. The spectrograms were generated using Sonic Visualiser (Release 4.3, Centre for Digital Music at Queen Mary, London, GB)