how to read a spectrogram !!
hello all!! i’m very glad that so many people have been able to enjoy seeing sound - often for the first time. i wanted to give people a little crash course in reading spectrograms, in case anyone wanted a little more explanation for what they’re looking at. enjoy!!
so to start off: a spectrogram is a visual representation of sound, including time, frequency, and amplitude (which we perceive as volume). time is measured across the x axis, and frequency is measured across the y axis. so if you’re looking at a full track in one image, higher pitched sounds later in the track would be in the top right, and lower pitched sounds at the beginning would be in the bottom left. it’s important to remember that a lot of audio is done in stereo, so there’s a left and a right channel that are able to play different sounds simultaneously. the top half of the image is the left channel, the bottom half is the right channel.
the amplitude shows up in the actual colors themselves. since i use audition to make spectrograms, the range of colors i work from is bright yellow to dark purple. the higher the amplitude, the “louder” the sound, the closer to that bright yellow it appears. the quieter, the closer it is to dark purple.
this can get tricky with perceived vs actual loudness. it’s important to remember that amplitude is more about how intense the actual sound is, and the volume is more subjective to individual hearing. generally, most of the “loud” yellow in a spectrogram will live in the lowest 1/4 of the image, even if those lower frequencies don’t sound like the loudest part.
the color aspect is best demonstrated in fade-outs. the undertale ost is chock-full of these. you can physically watch the song trail off from it's bright yellows and oranges, to the reds and purples, all the way to the color of silence: black.
anyways, once you start looking at the spectrograms and listening to the tracks together, it's pretty easy to follow along (especially if the track is broken up into any sort of chunks). you start looking at the shorter notes versus the holds, the cut offs vs the slides, how tracks start and end and build on themselves to create something that's really cohesive and cool!
all in all, i really didn’t expect to like spectrograms as much as i do. but being able to see sound and understand how it works ended up being really special to me :) whether you’re into the technical side of sound or just enjoy seeing the weird patterns and colors in music, i hope i’ve been able to bring about some small bit of creative joy. thank you !! <3
