In addition to the fundamental sound, though at a lower volume, ultraharmonics can be heard. This can be explained with the fact that, all the standing-waves can be formed which have nodes at the fixed string extremities.

It can be seen in the picture that their wavelength will be half, a third of the fundamental sound. As they propagate in the same string, their velocity will be similar to the speed of wave creating the fundamental sound, so the frequency of the upper harmonic sounds will be twice, three times as high. In the case of musical sounds, the sounds having double frequency are designated to be an octave higher.

The simultaneous contribution of the fundamental and ultraharmonic sounds to the formation of the sound and their relative volume will create the tone colour of the string sound.