Sonograms are a useful aid in learning about vocalizations, especially
subtle differences in sound that are difficult to distinguish by ear. A
sonogram is a visual representation of the sound, with time on the
horizontal axis and frequency (pitch) on the vertical
The sonogram below is typical of those shown in the All About Birds Online Bird Guide.
The first sonogram shows a 24-second recording of an American Goldfinch song. The song includes frequencies from about 2 kHz to 8 kHz.
The second sonogram provides an expanded view of a specific 2.5-second section of the first sonogram, noted by the white lines on the first sonogram. The greater detail reveals additional intricacies of the bird's song.
Viewing a sonogram, you can pick out features of a sound that you
might not have noticed just by listening. If you enjoy learning more
about bird sounds, consider recording the sounds you hear and
making your own sonograms.
You can make and explore sonograms of audio recordings with Raven software from the Cornell Lab of Ornithology.