spectrograms

/S P EH1 K T R AH0 G R AE0 M Z/
noun
  1. 1

    A visual representation of the spectrum of a sound changing through time.

  2. 2

    A visual representation of the spectrum of a celestial body's radiation.

Source: https://en.wiktionary.org/wiki/spectrogram, https://en.wiktionary.org/wiki/spectrograms