SpectraLayers’ Spectrograms

Most sounds, with the exception of sine waves, consist of different frequencies that vary in amplitude over time. The standard waveform graphs we’re familiar with show only two dimensions of this information: time and the overall amplitude of the signal. A spectrum analyser also shows only two dimensions, frequency and amplitude, but has no way to represent time. So, to represent how the different frequencies in a sound change and interact over time, a spectrogram of the sort used by SpectraLayers has to show all three dimensions of information – time, frequency and amplitude – in a two dimensional graph.

To achieve this, SpectraLayers shows time in the X-axis, frequency in the Y-axis, and represents the amplitude of those frequencies as changes in brightness and/or colour, depending on the display mode. The resulting display shows bright bands of fundamental frequencies, an everdarkening ladder of harmonic bands extending above those fundamentals, and speckled, chaotic areas that represent un-pitched noise and background. As an extra visualisation trick, SpectraLayers can shift into a quasi-3D view revealing comparative height (and amplitude) of the bands and colours in its spectrogram.

Different colour schemes and the ability to shift to a 3D view make the spectrogram more readable