CSL 1's the Gramle

Have you ever wondered how acoustic scientists are able to represent and analyze sound without listening to it? One tool in the toolbox is spectrogram analysis, which CSL members are becoming experts in. 

A spectrogram is a visual transformation of sound, which plots the time, frequency, and amplitude of the resonant frequencies of the sound. Speech sounds can be analyzed as complex waves, a type of periodic sound that can be decomposed into component waves that are simple periodic waves:

At any point in time, we can measure the relative amplitude of these component waves. Plotting these amplitudes creates a power spectrum. If we colour the power spectrum according to its height, and then turn it on its side, we get a spectral slice. Stacking the spectral slices of consecutive windows next to one another gets us the spectrogram.

Trained acoustic phoneticians can interpret the phenomena in a spectrogram to recover what kinds of sounds were produced. A fun way to practice this this skill is the gramle, a wordle-style game created by Dallin Tucker (and their dad and acoustic phonetician Ben Tucker) as their high school senior project. At CSL, we play the gramle at the beginning of every meeting to brush up on our spectrogram reading skills. 

In our most recent lab meeting, members were able to correctly identify the word in a mystery spectrogram on our first try! Congratulations to the lab members on our growing spectral sleuthing skills :).